static and kinetic friction coefficients

Appendix: Static and Kinetic Friction Coefficients for Selected Materials Peter J. Blau, Metals and Ceramics Division, Oak Ridge National Laboratory

THE DEFINITIONS for static and kinetic friction coefficients are given in the Glossary of this Handbook. The friction coefficient between solids sliding, or about to slide, over one another under the influence of a nonzero normal force is a function of several factors whose relative contributions vary on a case-by-case basis:

Composition of the materials Surface finish of each solid Nature of the surrounding environment Force holding the solids in contact (load) Velocity of relative motion Nature of the relative motion (for example, unidirectional, back and

forth, steady, variable, and so on) Nature of the contact (contbrming versus nonconforming surfaces) Temperature ot' the interfacial region Prior sliding history of the surfaces Characteristics of the machine and fixtures in which the materials are

affixed

No single source has generated a comprehensive list of friction coefficients tor materials under identical testing conditions; therefore, nearly all exist- ing handbooks rely on compilations of data produced under a variety of testing conditions. Readers should be aware of this shortcoming and use

the values only as very approximate guides, unless their applications are exactly the same as those methods used in generating the data.

The five tables of friction coefficient values in this Appendix contain both static and kinetic friction coefficients. They are arranged by material type as follows:

Table 1: metals on metals Table 2: ceramics on various materials Table 3: polymers on various materials Table 4: coatings on various materials Table 5: miscellaneous materials

It should be emphasized that the data in the tables are for unlubricated solids at room temperature and in ambient air. The reference list provided with each table lists both the sources of the data for the table and a brief description of the testing conditions used to generate these data, if such information was available in the reference. If accurate friction information is required for a specific application, the use of carefully simulated conditions or instrumentation of the actual machine should be conducted in lieu of using tabulated values because even a small change in contact conditions (for example, sliding speed or relative humidity for some materials) can result in a marked change in the measured or apparent friction coefficient.

ASM Handbook, Volume 18: Friction, Lubrication, and Wear TechnologyP.J. Blau, editor, p 70-75DOI: 10.1361/asmhba0002250

Copyright 1992 ASM International All rights reserved.

www.asminternational.org

Appendix: Static and Kinetic Friction Coefficients for Selected Materials / 71

Table 1 Friction coefficient data for metals sliding on metals Metals tested in air at room temperature

Friction Material coefficient

Test Fixed specimen Moving specimen geometry(a) Static Kinetic Ref

Ag Ag IS 0.50 Au IS 0.53 Cu IS 0.48 Fe 1S 0.49

AI AI IS 0.57 Ti IS 0.54

AI, alloy 6061-T6 AI, alloy 6061-T6 FOF 0.42 Cu FOF 0.28 Steel, 1032 FOF 0.35 Ti-6AI-4V FOF 0.34

Au Ag IS 0.53 Au IS 0.49

Brass, 60Cu-4OZn Steel, tool POR Cd Cd 1S 0.79

Fe IS 0.52 Co Co IS 0.56

Cr IS 0.41 Cr Co IS 0.4 I

Cr IS 0.46 Cu Co IS 0.44

Cr IS 0.46 Cu IS 0.55 Fe 1S 0.50 Ni IS 0.49 Zn IS 0.56

Cu, OFHC Steel, 4619 BOR . . Fe Co IS 0.4 I

Cr IS 0.48 Fe IS 0.51 Mg 1S 0.5 I Mo 1S 0.46 Ti IS 0.49 W IS 0.47 Zn IS 0.55

In In IS 1.46 Mg Mg IS 0.69 Mo Fe 1S 0.46

Mo IS 0.44 Nb Nb IS 0.46 Ni Cr IS 0.59

Ni IS 0.50 Pt IS 0.64

Pb Ag IS 0.73 Au IS 0.61 Co IS 0.55 Cr IS 0.53 Fe IS 0.54 Pb IS 0.90 Steel SPOF . .

0.34 0.23 0.25 0.29 2

0.24 3

0.82

0.8(



Pt Ni IS Pt IS

Sn Fe IS Sn IS

Steel Cu SPOF Pb SPOF

Steel, 1020 Steel, 4619 BOR Steel, 1032 AI, alloy 6061-T6 FOF

Cu FOF Steel, 1032 FOF Ti-6AI-4V FOF

Steel, 52100 Ni3AI, alloy RSOF IC-396M

Ni3AI, alloy IC-50 RSOF Steel, 1015 annealed BOR Steel, dual-phase BOR

DP-80 Steel, O2 tool BOR

Steel, mild Steel, mild BOR Steel, M50 tool Ni3AI, alloy IC-50 RSOF Steel, stainless Steel, tool POR Steel, stainless 304 Cu FOF Stellite Steel, tool POR Ti AI IS

Steel, 17-4 stainless POF Ti POF Ti FOF Ti-6AI-4V POF

Ti-6AI-4V AI, alloy 6061-T6 FOF Cu-AI (bronze) POF Nitronic 60 POF Steel, 17-4 stainless POF Steel, Type 440C POF

stainless Stellite 12 POF Stellite 6 POF Ta POF Ti-6AI-4V FOF Ti-6AI-4V POF

W Cu IS Fe IS W IS

Zn Cu IS Fe IS Zn IS

Zr Zr IS

0.64 0.55 0.55 0.74

0.47 0.32 0.31 0.36

0.23

0.54 0.48 0.47 0.55 0.43 0.41 0.36 0.38 0.36 0.44

0.35 0.45 0.53 0.36 0.36 0.41 0.47 0.51 0.56 0.55 0.75 0.63

0.80 1.40 0.54 0.38 0.25 0.23 0.32 1.08

0.70 0.74 0.55

0.49 0.62 0.68 0.53 0.21 0.60

0.48 0.40

0.36 0.38 0.27 0.31 0.31 0.37

0.29 0.36 0.53 0.30 0.31

(a)Test geometry codes: BOR, flat block pressed against the cylindrical surface ofa rotatingring; FOF. flat surface sliding on another fiat surface;IS, sliding down an inclined surface; POR, pin sliding against the cylindrical surface of a rotating ring; RSOF, reciprocating, spherically ended pin on a flat surface;SPOF, spherically ended pin on a flat coupon

REFERENCES/TEST CONDITIONS

1. E. Rabinowicz, ASLE Trans., Vol 14, 1971, p 198; plate sliding on plate at 50% relative humidity

2. "Friction Data Guide," General Magnaplate Corporation, 1988; TMI Model 98-5 slip and friction tester, 1.96 N (0.200 kgf) load, ground specimens, 54% relative humidity, average of five tests

3. J.F. Archard, ASME Wear Control Handbook, M.B. Peterson and W.O. Winer, Ed., American Society of Mechanical Engineers, 1980, p 38; pin-on-rotating ring, 3.9 N (0.40 kgf) load, 1.8 m/s (350 ft/min) velocity

4. A.W. Ruff, L.K. Ives, and W.A. Glaeser, Fundamentals of Friction and Wear of Materials, ASM International, 1981, p 235; fiat block-on-

rotating 35 mm (l-Y8 in.) diameter ring, 10 N (1.02 kgf) load, 0.2 m/s (40 ft/min) velocity

5. F.P. Bowden and D. Tabor, The Friction and Lubrication of Solids, Oxford Press, 1986, p 127; sphere-on-flat, unspecified load and velocity

6. P.J. Blau and C.E. DeVore, Tribol. Int., Vol 23 (No. 4), 1990, p 226; reciprocating ball-on-flat, 10 Hz, 25 N (2.6 kgf) load, 10 mm stroke

7. P.J. Blau, J. Tribology, Vol 107, 1985, p 483; flat block-on-rotating 35 mm (13/8 in.) diameter ring, 133 N (13.6 kgf) load, 5.0 cm/s (2.0 in./s) velocity

8. K.G. Budinski, Proceedings of Wear of Materials, American Society of Mechanical Engineers, 1991, p 289; modified ASTM G 98 galling test procedure

72 / Solid Friction

Table 2 Friction coefficient data for ceramics sliding on various materials Specimens tested in air at room temperature


Test Fixed specimen Moving specimen geometry(a1 Static Kinetic Ref

Ag Alumina RPOF Zirconia RPOF

AI Alumina RPOF Zirconia RPOF

Alumina Alumina SPOD Alumina SPOD Alumina SPOD WRA(b) SPOD WRZTA(c) SPOD ZTA(d) SPOD

Boron carbide Boron carbide POD Cr Alumina RPOF

Zirconia RPOF Cu Alumina RPOF

Zirconia RPOF Fe Alumina RPOF

Zirconia RPOF

0.37 0.39 0.75 0.63 0.50 0.52 0.33 0.53 0.50 0.56 0.53 0.50 0.61 0.43 0.40 0.45 0.35

Material Test

Fixed specimen Moving specimen geometry(a)

Friction coefficient

Static Kinetic Ref

Glass, tempered AI, alloy 6061-T6 FOF Steel, 1032 FOF Teflon(e) FOF

Silicon carbide Silicon carbide SPOD Silicon nitride SPOD Silicon nitride SPOD Silicon nitride SPOD

Silicon nitride Silicon carbide SPOD Silicon carbide SPOD Silicon carbide SPOD Silicon nitride SPOD

Steel, M50 tool Boron carbide POD Silicon carbide POD Silicon nitride POD Tungsten carbide POD

Ti Alumina RPOF Zirconia RPOF

Tungsten carbide Tungsten carbide POD

0.17 0.13 0.10

0.14 7 0.12 7 0.10 7 0.52 6 0.53 4 0.71 2 0.63 3 0.54 4 0.67 2 0.84 3 0.17 6 0.29 6 0.29 6 0.15 6 0.19 6 0.42 1 0.27 1 0.34 6

(a) Test geometry codes: FOF, Nat surface sliding on another flat surface; POD, pi n on disk (pin tip geometry not given); R POF, reciprocating pin on flat; SPOD, spherically ended pin on flat disk; SPOF, spherically ended pi n on a flat coupon. (b) WRA, silicon carbide whisker-reinforced alumina. (c) WRZTA, siheon carbide whisker-reinforced, zirconia-toughened alumina. (d) ZTA, zirconia-toughened alumina. (e) Teflon, polytetrafl uoroethylene

REFERENCES/TEST CONDITIONS

I. K. Demizu , R. W a d a b a y a s h i m , and H. Ishigaki , Tribol. Trans., Vol 33 (No. 4), 1990, p 505; 1.5 m m (0 .060 in.) radius pin reciprocat ing on a flat, 4 N (0.4 kgf) load, 0 .17 m m / s (0.0067 in#s) velocity, 50% relative humid i ty

2. P.J. Blau, Oak Ridge National Laboratory 3. P.J. Blau, Oak Ridge National Laboratory , 1.0 N (0 .10 kgf) load and

0.1 m/s (20 ft /min) velocity 4. P.J. Blau, Oak Ridge National Laboratory , 10 N (1.0 kgf) load and O. I

m/s (20 f t /min) veloci ty 5. C.S . Yust , Tribology of Composite Materials, P.K. Rohatg i , P.J,

Blau, and C.S . Yus t , Ed. , A S M Internat ional , 1990, p 27; 9.5 m m (3/8 in.) d iameter sphere -on-d i sk , 2 to 9 N (0.2 to 0 .9 kgf) load, 0 .3 m/s (60 ft /min) veloci ty

6. B. Bhushan and B .K. Gupta , table in Handbook of Tribology, Mc- Graw-Hil l , 1991; 20 N (2.0 kgf) , 3 m m / s (0.12 in. /s) veloci ty

7. "Frict ion Data Gu ide , " General Magnap la te Corporat ion, 1988; TMI Model 98-5 slip and friction tester, 1.96 N (0 .200 kgf) load, g round spec imens , 54% relative humid i ty , average o f five tests


Table 3 Friction coefficient data for polymers sliding on various materials Specimens tested in air at room temperature

Friction Material(a) coefficient

Test Fixed specimen Moving specimen geometry(b) Stat ic Kinetic Ref

Polymers sliding on polymers

Acetal Acetal TW 0.06 0.07 I Nylon 6/6 Nylon 6/6 TW 0.06 0.07 1 PMMA PMMA NSp 0.80 ' - - 2 Polyester PBT Polyester PBT TW 0.17 0.24 1 Polystyrene Polystyrene NSp 0.50 . - 2 Polyethylene Polyethylene NSp 0.20 -. 2 Teflon Teflon NSp 0.04 ' " ' 2

Teflon FOF 0.08 0.07 3

Dissimilar pairs with the polymer as the fixed specimen

Nylon 6 (cast) (extruded) Nylon 6/6 Nylon 6/6 (+ PTFE) PA 66 PA 66 (+ 15%

PTFE) PA 66 (PTFE/glass) PEEK PEEK (+ 15%

PTFE) PEEK (PTFE/glass) PEI PEI (+ 15% PTFE) PEI (PTFE/glass) PETP PETP (+ 15%

PTFE) PETP (PTFE/glass) Polyurethane(c) Polyurethane(d) POM POM (+ 15% PTFE) POM (PTFE/glass) PPS PPS (+ 15% PTFE) PPS (PTFE/glass) Teflon

UHMWPE

Steel, mild TPOD Steel, mild TPOD Polycarbonate TW Steel, mild TPOD Steel, 52100 BOR Steel, 52100 BOR

Steel, 52100 BOR Steel, 52100 BOR Steel, 521 O0 BOR

Steel, 52100 BOR Steel, 52100 BOR Steel, 52100 BOR Steel, 521 O0 BOR Steel, 52100 BOR Steel, 52100 BOR

Steel, 52100 BOR Steel, mild TPOD Steel, mild TPOD Steel, 52100 BOR Steel, 52100 BOR Steel, 52100 BOR Steel, 52100 BOR Steel, 521 O0 BOR Steel, 52100 BOR AI, alloy 6061-T6 FOF Cr plate FOF Cu FOF Ni (0.001 P) FOF Steel, 1032 FOF Ti-6AI-4V FOF TiN (Magnagold) FOF Steel, mild TOPD

0.25

0.24 0.09 0.13 0.15 0.27 0.t7 0.15

0.35 4 0.37 4 0.04 l 0.35 4 0.57 5 0.13 5

0.31 0.49 0.18

0.20 0.43 0.21 0.21 0.68 0.14

0.18 5 0.51 4 0.35 4 0.45 5 0.21 5 0.23 5 0.70 5 0.30 5 0.39 5 0.19 3 0.08 3 0.11 3 0.12 3 0.27 3 0.t4 3 0.12 3 0.14 4

Friction Material(a) coefficient

Test Fixed specimen Moving specimen geometry(b) Stat ic Kinetic Ref

Dissimilar pairs with the polymer as the moving specimen

Steel, carbon ABS resin POF OAO 0.27 6 Steel, mild ABS TW 0.30 0.35 1

ABS + 15% PTFE TW 0.13 0.16 1 Acetal TW 0.14 0.21 1

Steel, 52100 Acetal POD 0.31 7 HDPE POD . 0.25 7

Steel, carbon HDPE POF 0.36 0.23 6 LDPE POF 0.48 0.28 6

Steel, 52100 Lexan 101 POD .. 0.60 7 Steel, mild Nylon (amorphous) TW 0.23 0.32 1 Steel, carbon Nylon 6 POF 0.54 0.37 6 Steel, mild Nylon 6 TW 0.22 0.26 1 Steel, carbon Nylon 6/6 POF 0.53 0.38 6 Steel, mild Nylon 6/6 TW 0.20 0.28 1 Steel, carbon Nylon 6/10 POF 0.53 0.38 6 Steel, mild Nylon 6/10 TW 0.23 0.31 1

Nylon 6/12 TW 0.24 0.31 1 PEEK (Victrex) TW 0.20 0.25 1

Steel, carbon Phenol formaldehyde POF 0.51 0.44 6 Steel, 52100 PMMA POD 0.68 7 Steel, carbon PMMA POF 0.64 0.50 6 Steel, mild Polycarbonate TW 0.31 0.38 I

Polyesther PBT TW 0.19 0.25 1 Polyethylene TW 0.09 0.13 1

Steel, carbon Polyimide POF 0.46 0.34 6 Polyoxylmethylene POF 030 O. 17 6 Polypropylene POF 0.36 0.26 6

Steel, mild Polypropylene TW 0.08 0.1 t I Steel, carbon Polystyrene POF 0.43 0.37 6 Steel, mild Polystyrene TW 0.28 0.32 1

Polysulfone TW 0.29 0.37 I Steel, carbon PVC POF 0.53 0.38 6

PTFE POF 0.37 0.09 6 AI, alloy 6061-T6 Teflon FOF 0.19 0.18 3 Cr plate Teflon FOF 0.21 0.19 3 Glass, tempered Teflon FOF 0.10 0.10 3 Ni (0.001 P) Teflon FOF 0.22 0. t9 3 Steel, 1032 Teflon FOF 0.18 0.16 3 Ti-6AI-4V Teflon FOF 0.23 0.21 3 TiN (Magnagold) Teflon FOF 0.16 0.11 3

(a) ABS, acrylonitrile butadiene styrene; H DPE, high-densitypolyethylene; LDPE, Iow-densitypotyethylene; Lexan, trademark of the General Electric Co. (polycarbonate); nylon, one of a group of polyamide resins (see also PA); PA, polyamide; PBT, polybutylene terephthalate; PEEK, polyetheretherketone; PEI, polyetherimide; PETP, polyethylene terephthalate; PMMA,polymethylmethacrylate; POM, polyoxymethyiene PPS, polyphenylene sulphide; PTFE, polytetra fluoroethylene; PVC, polyvinyl chloride; UHMWPE, ultra high molecular weight polyethylene; Magnagold, product of General Magnaplate, Inc.; Teflon, trademark of E.I. Du Pont de Nemours & Co., Inc. (PTFE). (b) Test geometry codes: BOR, flat block-on-rotating ring; FOF, fl at surface sliding on another flat surface; NSp, not speci fled; POD, pin on disk; POF, pin on flat; TPOD, triple pin-on-disk; TW, thrust washer test. (c) Green polyurethane. (d) Cream-colored polyurethane

REFERENCES/TEST C O N D I T I O N S

1. " L u b r i c o m p (R) I n t e r n a l l y - L u b r i c a t e d R e i n f o r c e d T h e r m o p l a s t i c s and F l u o r o p o l y m e r C o m p o s i t e s , " B u l l e t i n 2 5 4 - 6 8 8 , ICI A d v a n c e d M a t e r i - a l s ; t h rus t w a s h e r a p p a r a t u s , 0 . 2 8 M P a (40 ps i ) , 0 . 2 5 m/ s (50 f t /m in ) , a f t e r r u n n i n g - i n for one ful l r o t a t i o n

2. F .P . B o w d e n and D. T a b o r , A p p e n d i x IV, The Friction and Lubrica- tion of Solids, O x f o r d P re s s , 1986; u n s p e c i f i e d t e s t i n g c o n d i t i o n s

3. " F r i c t i o n D a t a G u i d e , " G e n e r a l M a g n a p l a t e C o r p o r a t i o n , 1988; T M I M o d e l 98 -5 s l ip and f r i c t ion tes te r , 1 .96 N ( 0 . 2 0 0 kgf ) load , g r o u n d s p e c i m e n s , 5 4 % r e l a t i v e h u m i d i t y , a v e r a g e o f f ive tes t s

4. J . M . T h o r p , Tribol. Int., Vol 15 (No. 2), 1982, p 69; t h r e e - p i n - o n - r o t a t i n g d i s k a p p a r a t u s , 0 .1 m / s (20 f t /m in )

5. J . W . M . M e n s and A . W . J . de G e e , Wear, Vol 149, 1991, p 255 ; f la t b l o c k - o n - r o t a t i n g r i n g , 1.5 M P a ( 0 . 2 2 ks i ) p r e s s u r e , 150 N (15 kgf ) load , 0 .1 m / s (20 f t /min ) v e l o c i t y

6. R . P . S t e i jn , Metall. Eng. Quart., Vol 7, 1967, p 9; 12.7 m m ( 0 . 5 0 0 in . ) d i a m e t e r b a l l - o n - f l a t , 9 . 8 N ( 1 . 0 kgf ) l oad , 0 .01 m m / s (4 10 4 in . / s ) v e l o c i t y

7. N .P . S u h , Tribophysics, P r e n t i c e - H a l l , 1986, p 226 ; p i n - o n - d i s k , 4 . 4 N (0 .45 kgf ) l oad , 3 .3 c m / s (1 .3 in . / s ) v e l o c i t y , 6 5 % r e l a t i v e h u m i d i t y

74 / Solid Friction

Table 4 Friction coefficient data for coatings sliding on various materials Specimens tested in air at room temperature



AI, alloy 6061-T6 Cr plate FOF 0.27 0.22 Ni (0.001 P) plate FOF 0.33 0.25 TiN (Magnagold)(c) FOF 0.25 0.22

Au, electroplate 60Pd-40Ag, plate POF ., 2.40 60Pd-40Au, plate POF ., 0.30 70Au-30Ag, plate POF . .. 3.00 80Pd-20Au, plate POF . ,. 1.80 99Au- 1 Co, plate POF . - 2.40 Au plate POF . .- 2.80 Au-0.6Co, plate POF ., 0.40 Pd plate POF . - 0.60

Cr plate AI, alloy 6061-T6 FOF 0.20 0.19 Ni (0.001 P) plate FOF 0.19 0.17 Steel, 1032 FOF 0.20 0.17 Teflon(b) FOF 0.21 O. 19 Ti-6AI-4V FOF 0.38 0.33

Niobium carbide, Niobium carbide, FOF 0.19 0.13 coating coating

Ni (0.001 P) plate AI, alloy 6061-T6 FOF 0.26 0.23 Cr plate FOF 0.41 0.36 Ni (0.001 P) plate FOF 0.32 0.28 Steel, 1032 FOF 0.35 0.31 Steel, D2 tool FOF 0.43 0.33 Teflon(b) FOF 0.22 0.19 TiN (Magnagold)(c) FOF 0.33 0.26

Steel Cu film on steel SPOD 0.30 . In film on Ag SPOD 0.10 . . . In film on steel SPOD 0.08 . ' ' Pb film on Cu SPOD 0.18 . . .

Steel, 1032 Cr plate FOF 0.25 0.21 Ni (0.001 P) plate FOF 0.37 0.30 TiN (Magnagold)(c) FOF 0.31 0.28

Steel, type 440C TiC on type 304 POD 0.12 0.17 stainless stainless

TiN on type 304 POD 0.50 0.75 stainless

Material Test

Fixed specimen Moving specimen geometry(a)

Friction coefficient

Static Kinetic

Steel, bearing Chrome carbide POD SiC (CVD)(d) POD TiC (CVD)(d) POD TiN (CVD)(d) POD

Steel, stainless AI203, plasma- Ams sprayed

Cr plate Ams

Cr203, plasma- Ares sprayed

TiO2, plasma Ams sprayed

WC-12 Co, plasma- Ams sprayed

Teflon(b) Cr plate FOF Ni (0.001 P) plate FOF TiN (Magnagold)(c) FOF

TiC on type 440C AI POD stainless steel

Ti POD TiC on type 440C POD

stainless steel TiN on type 440C POD

stainless steel TiN on type 440C AI POD

stainless steel Steel, type 304 POD

stainless Ti POD TiC on type 440C POD

stainless steel TiN on type 440C POD

stainless steel TiN (Magnagold)(c) AI, alloy 6061-T6 FOF

Steel, 1032 FOF Teflon(b) FOF Ti-6AI-4V FOF TiN (Magnagold)(c) FOF

. 0.79

.. 0.23 . 0.25 . . 0.49 - 0 . 1 3 -

0.20 0.30-

0.38 0.14-

0.15 0.10-

0.15 0.11-

0.13 0.09 0.08 0.15 0.12 0.15 0.12 0.50 0.85

0.65 0 .80 5 0.22 0.20 5

0.25 0.20 5

0.27 0.40 5

0.29 0.41 5

0.50 0.76 5 0.05 0.06 5

0.65 0.45 5

0,30 0.26 1 0.38 0.31 1 0.16 0.11 1 0.26 0.23 l 0.25 0.21 I

Ref

(a) Ams, Amsler circumferential, rotatingdisk-on-disk machine; FOF, flat surface sliding on another flat surface; POD, pin on disk; POF, pin on flat; SPOD spherically ended pin-on-flat disk. (b) Teflon is a registered trademark of E.I. Du Pont de Nemours & Co., Inc. (polytetrafluoroethylene). (c) Magnagold is a product of General Magnaplate. Inc. (d) CVD, chemical vapor deposition


1. "Friction Data Guide ," General Magnaplate Corporation, 1988; TMI Model 98-5 slip and friction tester, 1.96 N (0.200 kgf) load, ground specimens, 54% relative humidity, average of five tests

2. M. Antler and E.T. Ratcliff, Proceedings of the Holm Conference on Electrical Contacts, 1982, p 19; sphere-on-reciprocating flat, 0.49 N (0.050 kgf) load, 1.0 mm/s (0.039 in./s) velocity

3. M.J. Manjoine, Bearing and Seal Design in Nuclear Power Machin- ery, American Society of Mechanical Engineers, 1967; flat plate-on- flat plate, 28 MPa (4.1 ksi) contact pressure, 0.25 mrn/s (0.010 in./s) velocity

4. F.P. Bowden and D. Tabor, The Friction and Lubrication of Solids, Oxford Press, 1986, p 127; sphere-on-flat , low-speed sliding, 39.2 N (4 kgf) load

5. B. Bhushan and B.K. Gupta, Handbook of Tribology, McGraw-Hil l , 1991, Table 14.16a; pin-on-disk, 12 N (1.2 kgf) load, 14 to 16 cm/s (0.55 to 0.63 in./s) velocity

6. B. Bhushan and B.K. Gupta, Handbook of Tribology, McGraw-Hil l , 1991, Table 14.65; pin-on-disk, 5 N (0.5 kgf) load, 1.0 cm/s (0.39 in./s) velocity, 50% relative humidity

7. B. Bhushan and B.K. Gupta, Handbook of Tribology, McGraw-Hil l , 1991, Table 14.12; Amsler disk machine, 400 rev/min, 250 N (26 kgf) load


Table 5 Friction coefficient data for miscellaneous materials Specimens tested in air at room temperature



Brick Wood UnSp 0.6 -. 1 Cotton thread Cotton thread UnSp 0.3 ' " ' 1 Diamond Diamond UnSp 0.1 ' - 1 Explosives(b)

HMX(c) Glass RPOF - - 055 2 PETN(d) Glass RPOF - 0.40 2 RDX(e) Glass RPOF . . . 0.35 2 Lead azide Glass RPOF - .. 0.28 2

[Pb(N3)2] Silver azide (AgN 3) Glass RPOF . . 0.40 2

Glass, tempered AI, alloy 6061-T6 FOF 0.17 0.14 3 Steel, 1032 FOF 0.13 0.12 3 Teflon(f) FOF 0.10 O. 10 3

Glass, thin fiber Brass StOD - 0 .16 - 4 0.26

Graphite StOD 0.15 4 Porcelain StOD - 0.36 4 Steel, stainless StOD . . . 0.31 4 Teflon(f) StOD 0.10 4

Glass, clean Glass (clean) UnSp 0.9 . . . . 1 1.0

Graphite, molded AI, alloy 2024 FOF 0.16 . -. 5 AI, alloy 2219 FOF 0.22 ' ' ' 5 Graphite, extruded FOF 0.20 O. 17 5 Graphite, molded FOF 0.18 0.14 5 lnconel X-750(g) FOF 0.16 ' ' ' 5 Steel, type 304 FOF 0.18 .. 5

stainless Steel, type 347 FOF 0.19 . . . 5

stainless



Graphite (clean) Graphite (clean) UnSp 0.10 Graphite (outgassed) Graphite (outgassed) UnSp 0.5-

0.8 Hickory wood, waxed Snow UnSp -- Ice Bronze UnSp -

Ebonite UnSp Ice UnSp 0.05

0.15 Ice UnSp . , . Ice FOF >0.01

Leather Metal (clean) UnSp 0.6 Metal Glass (clean) UnSp 0.5-

0.7 Mica (cleaved) Mica (cleaved) UnSp 1.0 Mica (contaminated) Mica (contaminated) UnSp 0.2-

0.4 Nylon fibers Nylon fibers UnSp 0.15-

0.25 Paper, copier Paper, copier FOF 0.28 Sapphire Sapphire UnSp 0.2 Silk fibers Silk fibers UnSp 0.2-

0.3 Steel (clean) Graphite UnSp 0.1 Wood (clean) Metals UnSp 0.2-

0.6 Wood (clean) UnSp 0.25-

0.5

"- 1 ' ' ' l

0.14 6 0.02 6 0.02 6 - - 6

0.02 >0.01

0.26

(a) FOF flat surface sliding on another flat surface; RPOF, reciprocating pin-on flat; StOD, strand wrapped over a drum; U nSp, unspecified method. (b) Explosives reported here were tested as reciprocating, single-crystal, flat-ended pin-on-moving flat. (c) HMX,cyclotetramethylenetetranitramine;(d) PETN,pentaerithritol tetranitrate. (e) RDX, cyclotrimethylene trinitramine. (f) Teflon is a registered trademark ofE.l. Du Pont de Nemours & Co., Inc. (g) lnconel is a product of INCO, Inc.


1. F .P . B o w d e n and D. T a b o r , A p p e n d i x IV, The Friction and Lubrica- tion of Solids, O x f o r d P res s , 1986; m e t h o d u n s p e c i f i e d

2. J . K . A . A m u z u , B . J . B r i s c o e , and M . M . C h a u d h r i , J. Phys. D, Appl. Phys., Vol 9, 1976 , p 133; r e c i p r o c a t i n g , s i n g l e - c r y s t a l f la t s l i d i n g o n s m o o t h f i red g l a s s s u r f a c e s , r a n g e 5 to 20 g f ( 0 . 0 4 9 to 0 . 1 9 6 2 N load) , 0 . 2 0 m m / s ( 0 . 0 0 8 in . / s ) v e l o c i t y

3. " F r i c t i o n D a t a G u i d e , " G e n e r a l M a g n a p l a t e C o r p o r a t i o n , 1988; T M I M o d e l 98-5 s l ip a n d f r i c t ion tes te r , 1 .96 N ( 0 . 2 0 0 kgf ) load , g r o u n d

s p e c i m e n s , 5 4 % r e l a t i v e h u m i d i t y , a v e r a g e o f f ive tes t s 4. P . K . G u p t a , J. Am, Ceram. Soc., Vol 74 (No. 7), 1991, p 1692; s t r and

l y i n g on a r o t a t i n g d r u m , 1 .96 N ( 0 . 2 0 0 k g t ) load , 8 .5 m m / s (0 .33 in . / s ) v e l o c i t y

5. M . J . M a n j o i n e , Bearing and Seal Design in Nuclear Power Machin- e ry , A m e r i c a n S o c i e t y o f M e c h a n i c a l E n g i n e e r s , 1967; f la t p l a t e - o n - f la t p l a t e , 28 M P a (4.1 k s i ) c o n t a c t p r e s s u r e , 0 . 2 5 m m / s ( 0 . 0 1 0 in . / s ) v e l o c i t y

6. F .P . B o w d e n and D. T a b o r , The Friction and Lubrication of Solids, O x f o r d P res s , 1986; u n s p e c i f i e d m e t h o d , 4 . 0 m/s (790 f t /min ) at 0 C

Front MatterTable of ContentsSolid Friction1. Introduction to FrictionSelected References

2. Basic Theory of Solid Friction2.1 Nature of Surfaces2.1.1 Topography2.1.2 Composition2.2.3 Subsurface Microstructure2.2.4 Friction under Lubricated Conditions

2.3 Basic Mechanisms of Friction2.3.1 History2.3.2 Friction of Metals2.3.3 Friction of Polymers2.3.4 Friction of Elastomers2.3.5 Friction of Ceramics2.3.6 Other Materials

2.4 Rolling Friction2.5 Future OutlookReferences

3. Frictional Heating Calculations3.1 Frictional Heating Nomenclature3.1.1 Bulk, Contact, and Flash Temperature3.1.2 Coefficient of Friction3.1.3 Heat Partition Factor3.1.4 Heat Source Time3.1.5 Pclet Number3.1.6 Real Area of Contact

3.2 Idealized Models of Sliding Contact3.2.1 General Contact Analysis3.2.2 Line Contact Analysis with Two Bodies in Motion3.2.3 Circular Contact Analysis with One Body in Motion

3.3 Correlation of Experimental Data with Calculated Values3.4 Factors Limiting the Accuracy of Calculations3.4.1 Effect of Transient Temperature3.4.2 Effect of Surface Layer3.4.3 Limitations of Calculations

AcknowledgmentReferences

4. Laboratory Testing Methods for Solid Friction4.1 Historical Development of Friction Testing Techniques4.2 Friction Models4.3 Friction Testing Techniques4.4 Friction Nomenclature4.4.1 Static Friction4.4.2 Kinetic Coefficient of Friction4.4.3 Stick-Slip Behavior4.4.4 Lubricated Friction

4.5 Standard Friction Tests4.5.1 ASTM Standards and Specifications4.5.2 Non-ASTM Standards

4.6 Performing a Valid Test4.6.1 System Modeling4.6.2 Material Documentation4.6.3 Surface Condition

4.7 Test Parameters4.8 Friction Measurements4.9 Friction DatabasesReferencesSelected Reference

5. Friction during Metal Forming5.1 Modeling of Friction5.1.1 Modeling of Flow through Conical Converging Dies5.1.2 Modeling of Strip Rolling

5.2 Measurement of FrictionAppendix: The Wave ModelThe Characteristics of Friction

References

6. Appendix: Static and Kinetic Friction Coefficients for Selected MaterialsLubricants and LubricationWearLaboratory Characterization TechniquesSystematic Diagnosis of Friction and Wear Test DataFriction and Wear of ComponentsMaterials for Friction and Wear ApplicationsSurface Treatments and Coatings for Friction and Wear ControlMetric Conversion GuideTemperature ConversionsAbbreviations, Symbols, and TradenamesIndex

static and kinetic friction coefficients

Documents