HARTIP-3000 PORTABLE HARDNESS TESTER

Transcription

1 PORTABLE HARDNESS TESTER OPERATIONAL MANUAL Bms Bulut Makina Sanayi Ve Ticaret Ltd. Şti. İkitelli Organize Sanayi Bölgesi Dolapdere Sanayi Sitesi Ada 4 No : 7-9 İkitelli / İSTANBUL-TÜRKİYE Phone : / Fax : web : bms@bulutmak.com

2 1. Forewords History Leeb Hardness Test Features And Applications Specifications Features Applications Designation Of Individual Parts Main Parts Special Features Of İmpact Devices Schematic Design Of The Impact Devices Symbols And Illustrations Symbols Measurement And Conversion Table Preparation Before Measuring Requirements For The Sample Requirements For The Weight Of The Sample Requirement For The Surface Hardened Layer Of The Sample Surface Of The Test Sample Should Not Be Magnetic Spport ring for small curvature Supporting The Samples During Testing Samples With Curved Surfaces Parameters Setting Operating For Setup And View Screen Measuring Procedure Delete Printing Maintenance Of The Impact Device Change Battery Fault Diagnosis Software For Hartip 3000 Instruction General Connection Installation Of Software Communication Data Transmitting System Accessories Rev:00 2 / 20

3 1. Forewords 1.1 History The Leeb measuring method was first brought into measurement technology in It is defined as the quotient of an impact body s rebound velocity over its impact velocity, multiplied by Harder materials produce a higher rebound velocity than softer materials. For a specific group of material (e.g. steel, aluminum. etc.), Leeb hardness value represents a direct relationship to its hardness properties. For ordinary metal, conversion curves of hardness HL versus other standard static hardness (HB, HV, HRC, etc.) are available, enabling you to convert HL into other hardness values. 1.2 Leeb Hardness Test (definition) An impact body with a spherical test tip made of tungsten carbide is propelled against the sample surface by a spring force and then rebounds back. At a distance of 1mm from the sample surface, the impact and rebound velocity of the impact body are measured by the following method: A permanent magnet embedded in the impact body, when passing through the coil in its coil holder, induces in the coil an electric voltage proportional to the velocities of the magnet. Leeb hardness is expressed by the following formula: HL=1000 (VB/VA) Where: HL is Leeb Hardness VB is the rebound velocity of the impact body VA is the impact velocity of the impact body The voltage characteristic of output signal, when the impact body passes through the induction coil is illustrated in the following figure: Voltage characteristic of output signal A Leeb s Hardness Tester measures the hardness of sample material in terms of Hardness Leeb (HL), which can be converted into other Hardness units (Rockwell B and C, Vicker, Briness and Shore D). Rev:00 3 / 20

4 1.3 Notation Of Leeb s Hardness When measuring the hardness of a sample material using the traditional static hardness testing method, a change of applied pressure will result in a change in the hardness reading. This will also happen during a Leeb s Hardness test when you change the impact device. In measuring the hardness of the same test sample with different impact devices, the Leeb s hardness values obtained will vary. For example: 720HLD 720HLC Because different converting curves are obtained from different impact devices, when converting hardness L into another hardness value the notation for the converted hardness value should include the impact device used. For example: Hardness HV converted from hardness L using impact device D+15 should be written as 22, 8 HV LD+15. Where: 22=Hardness value HL 8=Hardness value HV L=Leeb s Method LD+15=Impact device Hardness HRC converted from hardness L using impact device D should be written as 35, 9 HRCLD. Where: 35=Hardness value HL 9=Hardness value HRC L=Leeb s Method D=Impact device 2. Features And Applications 2.1 Specifications Accuracy : Main uncertainty +/- 0.5( referred to L=800 ) Repeatability : +/-6 L-units Measuring range : Hardness value L-units Operating temperature : , Impact device : Power : DC V, 4x V AA alkaline battery or rechargeable battery Weight : 550g Dimension : 195x84x38mm Standard package : HARTIP 3000 processor, Impact device type D, Test block, 4x1.5V AA alkaline battery, Cleaning brush, Carrying case, manual Optional accessories : Micro-printer, Impact device type DC, D+15, G, C, E, DL, Data managing software, Special support rings, Leather case, Connection cable (to PC or printer ) 2.2 Features Menu operation Large LCD display with back-light Impact devices : D, DC, D+15, G, C, E, DL L Value conversion to Brinell, Rockwell, Vicker and Shore value Measuring materials selection Measuring directions selection Probes are all interchangeable Rev:00 4 / 20

5 960 groups of data can be stored in individual 8 memory areas and can not be removed when the instrument turned-off or replacing batteries. Delete Average value on 3-9 times Data acquisition and print out RS 232 interface to PC 2.3 Applications Hardness tests on installed machines or steel structures: e.g. on heavy and large work-piece or on permanently installed system parts. Rapid testing of multiple measuring areas for examination of hardness variations over larger regions. Measuring hardness for produced parts at production line. Identifying metallic material stored in a warehouse. Ineffectiveness analysis of permanent parts, pressure -vessel, turbo generator. 3. Designation Of Individual Parts 3.1 Main Parts : Processor and the impact device Rev:00 5 / 20

6 3.2 Types Of Impact Devices 1 Loading tube 2 Guide tube 3 Coil holder with coil 4 Release button 5 Connecting cable leading to the indicating device with coil plug 6 Large supporting ring 7 Impact body 3.3 Special Features Of İmpact Devices Type Brief description D Universal standard unit. For the majority of hardness testing assignments. DC Extremely short impact device, otherwise same a specifications as for type D. Application : - in very confined spaces - in holes, cylinders - internal measurements on assembled machines D+15 Particularly slim front section Application : - hardness measurements in grooves and on recessed surfaces. DL Extremely slim front section Application : - in extremely confined spaces - at the base of grooves C Reduced impact energy (of that for type D). Application : - on surface hardened components, coatings - minimum layer thickness of 0.2mm. - on thin walled or impact sensitive components (small measuring indentation). E Synthetic diamond test tip (approx.5000 HV). Application : - for measurements in the extremely high range - e.g. cold work tool steel with carbide inclusions - on rolls in the hardness range up to 1200 HV Rev:00 6 / 20

7 G Increased impact energy(approx. 9 times that of type D) Application : - for measurements in the Brinell range - e.g. on heavy casting and forging - lower demands on measuring surface finish. 3.4 Schematic Design Of The Impact Devices Status at the moment of triggering the impact (impact spring stressed) 1 Loading tube 2 Guide tube 3 Coil with holder 4 Release button 5 Connection cable 3-pole 6 Large support ring 6a Small support ring 7 Impact body 8 Spherical test tip 9 Impact spring 10 Loading spring 11 Catch chuck 12 Material to be tested The model DC is not equipped with a loading tube; since it is loaded by means of a separate stick. The devices should not be disassembled; otherwise misadjustments in the spring system and the transmitter will occur. 4. Symbols And Illustrations 4.1 Symbols (Table 1) Symbols LD LDC LG LC LD +15 LE LDL Illustrations Leeb hardness value used with impact device D Leeb hardness value used with impact device DC Leeb hardness value used with impact device G Leeb hardness value used with impact device C Leeb hardness value used with impact device D+15 Leeb hardness value used with impact device E Leeb hardness value used with impact device DL Rev:00 7 / 20

8 (Table 2) Symbols HB HRB HRC HSD HV Illustrations Brinell hardness value Rockwell B hardness value Rockwell C hardness value Shore hardness value Vicker hardness value 4.2 Measurement And Conversion Table Range for measurement and conversion : (Table 3) IMPACT DEVICE D,DC L D : H R C H R B H B H V H S D STEEL CWT.ST ST.STEEL GC. IRON NC.IRON C.ALUM BRASS BRONZE COPPER IMPACT DEVICE D+15 LD+15: H R C H R B H B H V H S D STEEL CW. ST IMPACT DEVICE C L C: H R C H R B H B H V H S D STEEL CW. ST IMPACT DEVICE G L G: H R C H R B H B H V H S D STEEL GC.IRON NC.IRON IMPACT DEVICE E L E: H R C H R B H B H V H S D STEEL CW. ST IMPACT DEVICE DL LDL: H R C H R B H B H V H S D STEEL Rev:00 8 / 20

9 5. Preparation Before Measuring 5.1 Requirements For The Sample The surface temperature of the sample should be less than 120 C The samples must feature a metallic smooth, ground surface, in order to eliminate erroneous measurements brought about by coarse grinding or lathe scoring. The roughness of the finished surface should not exceed the following values: (Table 4) Types of impact devices D/ DC, D+15,DL,E G C Surface roughness of sample Ra 2μm 7μm 0.4μm 5.2 Requirements For The Weight Of The Sample For samples weighing over 5 kg and of compact shape, no support is needed. Samples weighing between 2-5 kg and also for heavier samples with protruding parts or thin walls should be placed on a solid support, in such a manner that they do not bend or move by the impact force. Samples weighing less than 2 kg should be firmly coupled with a stable support weighing over 5 kg. For coupling purposes, The coupling surface between the sample and base plate should be flat, plane parallel and ground. A thin proper layer of coupling paste is to be applied to the contact surface of the sample. The sample should be firmly pressed against the surface of the base plate by moving it with a circular motion. The direction of impact should be perpendicular to the coupling surface. For the coupling operation, the following prerequisites must be fulfilled: The contact surface of the sample and the surface of the base plate must be flat, plane parallel and ground. The direction of the test impact must be perpendicular to the coupled surface. Minimum thickness of the sample for coupling. (Table 5) Types of impact devices D/DC,D+15,DL,E G C 3mm 10mm 1mm Proper Coupling: Proper coupling requires a little experience. Insufficiently coupled samples produce large variations of individual measurements, L-values which are too low and the operation is characterized by a rattling noise upon impact of the test tip. Example for coupling a test piece with a base plate: Rev:00 9 / 20

10 Application of the coupling paste (As thin as possible). Mutual rubbing of both parts while firmly pressing the sample against the base plate. A particular advanced of coupling is the possibility of obtaining a very uniform, rigid connection between the sample and the support, totally eliminating stresses at the sample surface. The resulting variation in measured values is very low. 5.3 Requirement For The Surface Hardened Layer Of The Sample Surface -hardened steels and especially case-hardened steels produce L-values which are too low when case-hardening depth is small because of their soft core.when measuring with impact device D, DC, D+15, DL, E the depth of the hardened layer should be no less than 0.8 mm. When measuring with impact device C, the depth of the hardened layer should be no less than 0.2 mm. (Table 6) Types of impact devices D/DC, D+15,DL,E C Min. layer thickness for surface hardening 0.8mm 0.2mm 5.4 Surface Of The Test Sample Should Not Be Magnetic 5.5 Spport ring for small curvature 5.5 For test sample of curving surface with radius of curvature R less than 30mm, a small support ring should be used. Rev:00 10 / 20

11 5.6 Supporting The Samples During Testing (Table 7) Types of impact devices Classification of samples heavy medium-weight light-weight D/DC, D+15,DL,E more than 5 kg 2 5 kg kg G more than 15 kg 5 15 kg kg C more than 1.5kg kg kg When measuring hardness with HARTIP 3000, the following has to be noticed: Despite the low mass of the impact body and low impact energy, a relatively large impact force of short duration is generated when the impact body hits the measuring surface. (Table 8) Types of impact devices D/DC, D+15, DL, E G C Max. impact force 900N 2500N 500N For heavy samples of compact shape, no particular precautions are necessary. Smaller and lighter samples or workpieces yield or flex under this force, producing L- values which are too small and of excessively large variation. Even with big or heavy workpieces it is possible for thin-wall regions or thinner protruding parts to yield upon impact. Depending on the frequency of the resilient yielding action, the measured L-value may be too small or too large. In many situations, potential problems can be checked in the following manner: a) Medium-weight samples and also heavier samples with protruding parts or thin walls should be placed on a solid support in such a manner that they do not move or flex during the test impact. b) Light-weight samples should be rigidly coupled with a non-yielding support such as a heavy base plate. Clamping in a vice is of no value, since the samples become exposed to stress and because complete rigidity is never attained. As a rule, the measured L-values would be too small and show excessive variations. 5.7 Samples With Curved Surfaces Impact testers only work properly, if the impact body has a certain position in the guide tube at the moment of impacting the test surface. In the normal position, automatically present when testing flat and convex-cylindrical samples (such as round samples), the spherical test tip is located exactly at the end of the guide tube. However, when testing spherically or cylindrically shaped concave surfaces, the impact body remains further within the guide tube or protrudes further therefrom. Thus, with such types of curved surfaces, it is to be observed that radii of curvature do not drop below the values indicated in the following Fig. Curved surfaces should always be tested with the small support ring. Rev:00 11 / 20

12 Impact device types D/DC, D+15, C and E Rmin=30mm Impact device type G Rmin=50mm For impact devices D, DC, D+15, C and E, special support rings are available to accommodate smaller radii on convex or concave surface. 6. Keyboard HARTIP 3000 (Fig 1) ON/OFF ESC START O ENTER PRINT DEL PC : Turn-on / off the instrument : Exit from the screen : Move the cursor left or right : Move the cursor up or down : Start measuring : Back light : Confirm the set up : Print out : Delete error data : To computer Turn on the instrument Press ON/OFF to turn on the instrument. When initial use, if you want to change the parameters, press ESC back to the mode of main menu (Fig 2) if the current screen is not in the main menu. 6.1 Parameters Setting Main menu There are 7 items of selection in two screens 1. Impact Device 2. Material 3. Conversion 4. Setup and view 5. Memory 6. Date 7. Language (Fig 2) By pressing to determine and then press ENTER to confirm Selection of Impact device In the mode of main menu, choose item 1 and press ENTER into the mode of impact device selection as Fig 3. By press to choose the impact device you want and then press ENTER to confirm. Rev:00 12 / 20

13 D DC D+15 C G E DL (Fig 3) Materials selection In the mode of main menu, choose item 2 and press ENTER into the mode of Materials selection as fig 4. Nine materials will be shown on the three pages.then press arrow to move the cursor to select the material requested and then press ENTER to confirm. Steel /Cast Steel Alloy Tool Steel Stainless Steel Grey Cast Iron Spherical Iron Cast Aluminium Brass Bronze (Fig 4) Wrought Copper Conversion of hardness In the mode of main menu, choose item 3, press ENTER into the mode of conversion screen as fig 5 HV HSD HB HRB HRC (Fig 5) Choose the right conversion you want and press ENTER to confirm. If you choose , only Leeb hardness value will be shown on the LCD when measuring Setting of the memory In the mode of main menu, move the cursor to item 5 and press ENTER, the screen will display as fig 6. / 1 / 2 OFF / 4 / 8 (Fig 6) HARTIP 3000 has a memory capacity of 960 data on the whole memory region. The memory region has a choice of 1, 2, 4 or 8 sub-region which represents the whole memory region is divided into 1, 2, 4 or 8 sub-region. Each sub-region has a memory capacity of 960/n (n is the number of sub-region). For example, if you choose 8, it means the whole memory region is divided into 8 memory sub-regions that is1/8, 2/8... 8/8. Each subregion has a memory capacity of 120 data. The function can distinguish the different data acquired under the different measuring condition and parameters and it is convenient for view and collective printing. In this screen, firstly choose memory segmentation (1, 2, 4, 8) by press, or and press ENTER. Then press, or to choose sub-region or memory OFF and press ENTER to confirm. Once you choose a memory sub-region say 1/4, the screen appears Load and Save needed to set as Fig 7. Rev:00 13 / 20

14 1 2 2/4 Load Save 8 (Fig 7) Load means download the data stored in this sub-region to working screen. If this sub-region is empty, this function means open a new sub-region. But the parameters will remain as last operation. Save means all updated data and parameters on working screen will be stored in the sub-region you just selected. There are two ways to store test values. One is opening a memory region at first, and then take measurement. The other way is to take measurement at first in memory OFF and then open a memory region to save. Please note, if you change memory segmentation (1, 2, 4, 8) from one to another, the data stored in last one will be removed by this change Setting of the Test Date In main menu, choose item 6, press ENTER into the mode of setting date screen as fig 8. 07, (Fig 8) Month and Day will be shown on the first line; Year will be shown on the second line.press or to determine Month, Day or year and press or to input the current test date. Then press ENTER to confirm Language selection In main menu, choose item 7, press ENTER into the language selection screen.press or to choose and press ENTER to confirm Setup and view In main menu, choose item 4 and press ENTER into Setup and view screen as fig 9. In this screen, you can choose the impact direction, mean values, print or transfer to PC. Furthermore, you can also review updated test measurements, all kinds of conversed value, max. & min., mean square error of total test, ser. value and stored data in memory. (1) (2) (3) NO. LD HRC OFF 0 SN PC (4) (5) (6) (7) (8) (Fig 9) Rev:00 14 / 20

15 In the Setup and view screen (1) Number (2) Setting of Leeb hardness (3) Setting of conversion value (4) Setting of impact direction (5) Setting of memory sub-region, OFF means memory off. (6) Counter of measuring (7) Setting times of mean value: 3-9 times available to choose, SN means no impact times to be set. (8) Setting of connection to printer or computer, PR means to connect to printer, PC means to connect to PC. 6.2 Operating For Setup And View Screen (Fig 9) Setting of Leeb hardness value Move the cursor by or to the place (2), press or to change Leeb value or space. If you choose space, the display in working screen will only show conversion value in large letters Setting of conversion value Move the cursor by or to the place (3), press or to change conversion value you desired. If you choose space, the display in working screen will only show Leeb hardness value in large letters Setting of impact direction Move the cursor by or to the place (4), press or to change the impact direction Setting of memory sub-region Move the cursor by or to the place (4), press or to change memory subregion. You can read data stored in the sub-region you opened by press or and delete any data by press ESC. If you want to delete all data in this sub-region, press and hold, then press ESC. Every time of entering into Setup and view screen, the LCD always displays the updated measurements in working screen. Although you may changed sub-region and displayed, when you move out the cursor,the LCD will automatically redisplay the updated data in working screen Setting times of mean value Move the cursor by or to the place (7), Press or to change impact times on average. There are 3-9 impact times available to choose. By pressing or, when you choose SN, the LCD will automatically display maximum, minimum, mean value on total measurements and mean square error value. Please note, if the updated display is just SN, you must press or to read the above display Setting of connection to printer Move the cursor to the place (8), press or to choose PR or PC. PR means to print and PC means to connect to computer. Space shadow means not to transfer data out. There are two ways to transfer data out. One way is to transfer out data while taking every measuring. The other way is used as a data logger. That is after all measurements are completed, print out the data you want. Please note: In Setup and view screen, every change should be confirmed by pressing ENTER. Press ESC back to main menu or press START to enter into working screen at any mode. At working screen, you can quickly enter into Setup and view screen by pressing and hold ENTER, and then press ESC. Rev:00 15 / 20

16 6.3 Measuring Procedure After all selections are completed, press START, the LCD displays the selected material and date for about 2 seconds. Then into working screen which has two screen versions A and B. (Fig 10) The screen A means to individually display Leeb hardness value or its conversion value and the screen B means to display both Leeb hardness value and its conversions simultaneously. NSV 0 X5 Working Screen A NO LD HRC NSV 0 _ X5 Take measuring with impact device: Working Screen B (Fig 10) Loading: Press down the loading tube to lock the impact body inside the impact device. Placing: Place and press the support ring beneath impact device on the surface of measured workpiece. The distance of two test points should be no less than 3mm. Starting: Press the button on top of the impact device to release the locked impact body to complete the measurement. When one measurement is finished, the measured Rev:00 16 / 20

17 hardness value, total measuring times, number of impacts for average and testing numbers will be shown on LCD. While testing, the impact device, work-piece and body must be stable. 6.4 Delete While testing, if a value with significant error, press DEL to delete the data. 6.5 Printing PT micro printer (optional) Baud: Connect the instrument to a printer with a connection cable, at the same time, connect the power adapter with 220V 50Hz power to the printer and a red/green lamp on the printer will light up. Press SEL key to disable the green lamp to be ready for printing. For further information, please read the instruction of printer Printing on line At the Setup and view screen as Fig 9, move the cursor to the place 8, press or key to select PR, then press ENTER to confirm and then press START. After one test is completed, the value will be automatically printed out Printing off line After all testing finished, press ESC key and select Setup and View screen as fig 9, shift the cursor to the place 8, press or key to select PR, if the printer is already connected with instrument, press PRINT key to have the data printed out. If you want to print stored data in memory, firstly recall the stored data on to Setup and View screen, then press PR key to activate printing. 6.6 To end the testing by press ESC key. 7. Maintenance And Repair Do your best to avoid shock, heavy dust, damp, strong magnetic field, and oil stain. 7.1 Maintenance Of The Impact Device The devices do not require any particular care other than periodic cleaning of the impact body and the guide tube after performing approximately tests. During cleaning, the following procedures need to be observed: Unscrew support ring and remove impact body from guide tube. Clean off any dirt and metallic dust from the impact body and the spherical test tip. Clean guide tube with the special brush provided. Do not apply oil to any parts for the impact device. 7.2 Change Battery You can change the battery at any time, if use AA alkaline battery, please take out of the battery from battery house if no use for a long time. 7.3 Fault Diagnosis If finding any abnormalities, please read our fault diagnosis first No digital readout-dead batteries/batteries improperly poled/no contact at negative battery pole/no battery in holder/indicating device too cold (temp. <0)/fuse broken Digital display does not move-poor cable contact or cable broken/the tested material is extremely homogenous. Rev:00 17 / 20

18 7.3.3 No impact occurs-impact body is not or improperly located in the impact device/impact body does not release or cannot be loaded Marked deviation of individual L-values or L-values constantly too lowmeasuring area inadequately prepared/the tested material is extremely inhomogeneous or porous/sample is insufficiently supported/sample exhibits large local hardness differences e.g. at the transition seam to the base material/impact direction has been change between the individual impacts L-values at the standard test block constantly too low-impact device contaminated/spherical test tip cracked (e.g. due toimpact against tungsten carbide)/support ring does not have rubber pad L-values at the standard test block constantly too high-spherical test tip flattened (impact against tungsten carbide, wear)/standard test block damaged or full of indentations. 8.Software For Hartip 3000 Instruction 8.1 General The Hartip 3000 software requires running in the condition lf Windows. Before transmitting the data from Hartip 3000 to PC, you must install the software in the PC with Hartip 3000 software disk. Using the software, you can store, print, change conversion and means, view graphs on bar and line, delete unworkable data and so on. 8.2 Connection Connect Hartip 3000 hardness tester to com1 serial port of PC (or com2 using standard adapter 9 pin to 25 pin which can be ordered optionally) with connection cable. 8.3 Installation Of Software Insert the disk to PC driver A (or B depands on the user s system) and enter into driver A (or B) Double click the file setup and then follow the given instructions till installation finished. A file HARTIP will be automatically created in the hard disk of PC. 8.4 Communication Open the file HARTIP, a software title page will display. You can press any key or click the button on the title page with mouse or wait for a few seconds to go into indicates to wait for connecting on line Turn on the tester and go into the SETUP/VIEW screen. Move the shadow to the place 8 as Fig 9, press or key to select PC until the words Login please on PC id replaced by the words On line. 8.5 Data Transmitting There are two ways to transmit the data from Hartip tester to PC. One is transmitting on line when testing and the other is block transmitting after testing Transmitting on line when testing After communicating, press key START. The parameters which are set on the Hartip such as probe type, material selected and impact direction will be transmitted to the software screen. Then take measurement, the results will be displayed while testing. Rev:00 18 / 20

19 8.5.2 Transmitting data after testing Firstly load the data from memory onto the screen of Hartip After communicating, press key PC and all data selected will be loaded to the computer software page. 9. System Accessories Support Rings for: Impact Devices D/DC/D+15/C/E Part designation and dimensions: D6 D6a D6b/D+15 Z Z Z Φ mm Φ mm Φ mm mm mm mm Suitable for the following test surfaces plane cylindrical R 60mm hollow-cylindrical spherical hollow-spherical plane cylindrical R 30mm hollow -cylindrical spherical hollow-spherical plane cylindrical R 30mm hollow-cylindrical spherical hollow-spherical cylindrical R 10mm-15mm R 14.5mm-30mm R 25mm-50mm R<10mm not possible R 30mm D6/D6a Rev:00 19 / 20

20 hollow-cylindrical HZ mm R 11mm-13mm HZ mm R 12.5mm-17mm HZ mm R 16.5mm-30mm R<11mm not possible R 30mm D6a spherical K Φ mm R 10mm-13mm K Φ mm R 14.5mm-30mm R<10mm not possible R 30mm D6/D6a hollow-spherical HK Φ 17 5mm R 11mm-13mm HK Φ 18 5mm R 12.5mm-17mm HK Φ 20 5mm R 16.5mm-30mm R<11mm not possible R 30mm D6a UN Φ mm Impact Device G Part designation and Suitable for the following test dimensions: G6 surfaces Φ mm plate cylindrical R 100mm hollow-cylindrical spherical hollow-spherical G6a Φ mm plate cylindrical R 50mm hollow-cylindrical spherical <: less than hollow-spherical : equal to or greater than Rev:00 20 / 20