Surface Roughness Testing

Transcription

1 Surface Roughness Testing J-1

2 Summary of Roughness Parameters Commonly Used Arithmetical mean deviation of the profile R a (ISO 4287, DIN 4768) The arithmetical mean deviation of the profile Ra is the mean value of the absolute value of the profile departure y within the reference length l. Max. profile valley depth R max (DIN 4768) The max. profile valley depth R max is the largest of the existing single roughness depths i in the total measuring length l m. According to ISO 4288 and DIN Part 1, this parameter is also called R y max. Mean roughness depth R z DIN (DIN 4768) The mean roughness depth R z is the arithmetical mean of the single roughness depths of successive sampling lengths l e. According to ISO 4287 and DIN 4762, the parameter R z DIN is also called R y5. Because R z is named differently in DIN 4768 and ISO 4287, this paramater is also called R z DIN and R z ISO. When the parameter R z is measured according to DIN, it is generally admitted that the extrem value ISO is also matched providing that R z DIN is not exceeding R z ISO. Application of Roughness Comparison Specimens For a long time, these specimens for testing the surface finish quality have proven their value in practical use. They serve for touch and/or sight comparisons with the surface of the workpieces that are manufactured using the same method. Condition is that materials have to be comparable. The comparison of the roughness of the workpiece surface is not quantitatively expressed. The extent to which the surfaces of both the specimen and the workpiece are matched is appreciated subjectively only. Sight comparison requires optimum light source angle. For small surfaces, the use of a magnifying glass with up to 8x magnification is recommended. Touch comparison is made using the finger nail or a small cooper piece like a coin, for instance. l t R max 4 5 y m R a 0 x Ie 5 x l e = lm l Pre-travel length Post-travel length J-2

3 RUGOTEST Roughness Comparison Specimens For touch and/or sight comparisons with the surface of workpieces DIN 4769 part 1 and part 2 Rust-resistant, Nickel Specimens for roughness comparison are no reference specimens. They are not suitable for calibrating surface roughness testers. Leather case Sets of roughness comparison specimens for individual machining methods according to ISO roughness parameters RUGO- TEST No. Number of single specimens ISO roughness parameters RUGOTEST A4 consisting of the following single specimens : Metal working 1 27 N2 to N Hand grinding 2 6 N6 to N Shot blasting 3 18 N6 to N Hand filing 4 6 N6 to N RUGOTEST A6 consisting of the following single specimens : Planing N6 to N Turning N5 to N Face milling N5 to N Surface grinding N1 to N Cylindrical grinding N1 to N Spark erosion N5 to N10 RUGOTEST No. mm x x x x x x x x x x x x A4 330 x A6 330 x g J-3

4 Executions for individual machining methods according to ISO roughness parameters ISO roughness parameters N0 N1 N2 N3 N4 N5 N6 N7 N8 N9 N10 N11 Arithmetical mean deviation of profile R a µm 0,0125 0,025 0,05 0,1 0,2 0,4 0,8 1,6 3,2 6,3 12,5 25 µin Ten point height of irregularities R z ISO µm / µin Characteristic related data may differ depending on the machining method applied RUGO- TEST No. Number of single specimens Metal working 1 27 Side milling 3 Face milling 5 Turning/Planing 5 Grinding 6 Lapping 4 Finish grinding/honing Hand grinding Shot blasting 3 18 Shot-blasting mean spherical coarse 3 fine 6 angular coarse 3 fine Hand filing 4 6 straight 3 crossed Hand polishing 5 10 Surface form cylindrical 5 plane Planing Turning Face milling Plane grinding Circular grinding Spark erosion Execution according to Charmille roughness parameters (VDI 3400) Charmille roughness parameters Arithmetical mean deviation of profile R a µm 0,40 0,56 0,80 1,12 1,60 2,24 3,15 4,5 6,3 9,0 12,5 18,0 Number of single specimens Spark erosion 12 J-4

5 Measuring principle of the contact system, piezoelectric 3-digit LC display 0,01 µm 1 µin See adjoining table TESA RUGOSURF Surface Roughness Gauge Mobile and versatile roughness gauge that can be used in manufacturing cells, receiving inspection and measurement laboratory Solidly built and easily handle The selected accessories allow to inspect a wide variety of forms and shapes of workpiece surfaces Measurements can be performed in virtually any position Measure small bores as well as grooves. The following roughness parameters can be measured: Arithmetical mean deviation of the profile R a ISO 4287, DIN 4762, DIN 4768 Max. height of the profile R y ISO 4287, DIN 4762 Max. profile valley depth R max ISO 4287, DIN 4768 Mean roughness depth R z DIN DIN 4768 also called corresponds to R y5 ISO 4287 Integrated drive unit. Interchangeable probes with either a transverse or parallel chisel stylus. Easy-to-use parameter selection switch. Comfortable, reliable reading of the results on the digital display. Digital output for a direct value transmission to TESA PRINTER SPC or to a computer unit. Classe 2 (± 10 %) according to DIN 4772 Cut-off: 0.8 mm / 0.03 in (ANSI 2RC filter) The total measuring lenght l m may be set for 1, 3 or 5 cut-off-lenghts 4 possible measuring positions of the stylus Feed rate V t : 5 mm / s mn RS V alkaline batery, IEC 6F h Durable cast aluminium housing 10 C to 45 C - 20 C to 65 C Basic instrument without probe: 140 x 76 x 25 mm basic instr. without probe: 435 g TESA RUGOSURF Surface Roughness Gauge delivered with the following standard accessories : standard probe with a 90 conical diamond stylus, 5 µm in tip radius roughness standard, nominal value Ra = 3,1 µm respectively 122 µin 1 bottom plate, associated with the reference standard V alkaline battery, IEC 6F22 3,8 Plastic case Declaration of conformity. Available upon request: reference standard No with calibration certificate µm µin Evaluation lenght l / l m mm in Total displacement length l t mm in Cut-off mm R a 0,03 6, , , x 0,8 R y 0,2 25, , , x 0,8 R a / R z DIN / R max 0,2 25, , , x 0,8 J-5

6 Special Accessories for TESA RUGOSURF Surface Roughness Gauge Transport packing ø7,1 ø2,4 1,3 1,8 19,3 3,8 1,3 3,8 70,6 Transverse chisel probe Sapphire chisel stylus for measuring small shafts, sharp edges etc. 90 chisel stylus,10 µm in radius. Parallel chisel probe Diamond chisel stylus for lateral measurement on small shafts, sharp edges etc. 90 chisel stylus, 10 µm in radius. Small bore probe For measuring diameters ranging from 3,2 mm respectively 1 / 8 in, 90 conical diamond stylus, 10 µm in tip radius ,6 14,2 ø2 2,8 Groove bottom probe For measuring hard-to-reach recesses, 90 conical diamond stylus, 10 µm in tip radius Measuring stand Clamp for vertical and horizontal positioning of the instrument. Adjustable device for height position. Universal stand 250 x 270 mm cast iron bottom plate, with ground measuring face. Vertical column, 31,7 mm in diameter, 213 mm high. Adjustable swivel clamp Vee fixture Bottom plate with a Vee for holding shafts up to 25 mm or 1 in dia. Clamp for height adjustment. All parts are nickel-plated. Vee adaptor kit for checking hard-toreach surfaces on shafts 3 interchangeable Vees for diameters from 5 to 125 mm respectively from 0.19 to 5 in. Bottom plate with Vees For measuring small parts (min. surface 19 x 19 mm) and short shafts with diameters from 6,35 mm respectively 0.25 in, and length of 38 mm or 1.5 in J-6