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Tooth lock washers, inch (ASME B18.21.1): internal and external tooth star washers, #2 to 1 in, ID, OD, thickness + ring envelopes

What are the ID, OD and thickness of a #8 or 1/4 internal tooth or external tooth lock washer? · Standard part · basis: AFT Fasteners and Tanner Bolt (internal tooth, ASME B18.21.1-2009, identical numbers) and Tanner Bolt with Aspen Fasteners (external tooth, B18.21.1-2009 and -1999, identical numbers); 20 ring envelopes as files

Also called: internal tooth lock washer dimensions, external tooth lock washer dimensions, #8 star washer od, 1/4 external tooth lock washer od, #10 internal tooth lock washer id, star washer size chart, tooth lock washer thickness 1/4, 3/8 internal tooth lock washer, star washer 5/16 od, asme b18.21.1 tooth lock washer, internal vs external tooth washer, tooth lock washer stl

Exact dimensions. Every file is drawn at true size with no tolerance added. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your process's clearance before making the part. Mating features

length
31.6 mm
width
31.6 mm
height
1.7 mm

Notes

  • Inches (OD also in mm). Internal tooth: #2 to 1-1/4 in; external tooth: #2 to 1 in. Each row: nominal size, inside diameter max / min, outside diameter max / min, thickness max / min. AFT's and Tanner's internal-tooth tables carry the same numbers for every size. Tanner's external table (2009) and Aspen's (1999) also agree on every size, including the odd 'nominal' of 0.086 / 0.563 for #2 and 9/16 (Aspen rounds 9/16 to .563; Tanner prints .5625).
  • Column reading: the PDFs print a leading decimal that is the size's nominal diameter, then the inside diameter pair (larger first on the sources that label it 'max'), the outside pair and the thickness pair. The labels in the extracted PDFs are partly garbled, so max / min follow the larger / smaller of each pair; check against the standard if a figure matters. One AFT / Tanner row not tabulated: '1/8 pipe' (a pipe-size washer printed with a different column pattern).
  • Number of teeth is not printed in any table read here, and is left out. Tooth shape (twist angle, tooth width) is not published as numbers.
  • Files: rings (annuli) at the ID min and OD max of the washer and the maximum thickness, for #4, #6, #8, #10, 1/4, 5/16, 3/8, 1/2, 5/8 and 3/4 in, internal and external. Teeth, their twist and the washer's spring are not modelled. McMaster-Carr sells tooth lock washers with per-part STEP; linked, not copied. Metric forms: serrated-lock-washers-din-6798. Split washers: split-lock-washers-inch-asme-b18-21-1.

Tooth lock washers, inch (ASME B18.21.1): internal and external… size chart

typesizenominal (in)ID max / min (in)OD max / min (in)thickness max / min (in)OD max (mm)
internal tooth#20.0860.095 / 0.0890.200 / 0.1750.016 / 0.0105.08
internal tooth#30.0990.109 / 0.1020.232 / 0.2150.016 / 0.0105.89
internal tooth#40.1120.123 / 0.1150.270 / 0.2450.018 / 0.0126.86
internal tooth#50.1250.136 / 0.1290.280 / 0.2550.020 / 0.0147.11
internal tooth#60.1380.150 / 0.1410.295 / 0.2750.022 / 0.0167.49
internal tooth#80.1640.176 / 0.1680.340 / 0.3250.023 / 0.0188.64
internal tooth#100.190.204 / 0.1950.381 / 0.3650.024 / 0.0189.68
internal tooth#120.2160.231 / 0.2210.410 / 0.3940.027 / 0.02010.41
internal tooth1/40.250.267 / 0.2560.478 / 0.4600.028 / 0.02312.14
internal tooth5/160.3120.332 / 0.3200.610 / 0.5940.034 / 0.02815.49
internal tooth3/80.3750.398 / 0.3840.692 / 0.6700.040 / 0.03217.58
internal tooth7/160.4380.464 / 0.4480.789 / 0.7400.040 / 0.03220.04
internal tooth1/20.50.530 / 0.5120.900 / 0.8670.045 / 0.03722.86
internal tooth9/160.56250.596 / 0.5760.985 / 0.9570.045 / 0.03725.02
internal tooth5/80.6250.663 / 0.6401.071 / 1.0450.050 / 0.04227.20
internal tooth3/40.750.795 / 0.7691.245 / 1.2200.055 / 0.04731.62
internal tooth7/80.8750.927 / 0.8941.410 / 1.3640.060 / 0.05235.81
internal tooth11.1.060 / 1.0191.637 / 1.5900.067 / 0.05941.58
internal tooth1-1/81.1251.192 / 1.1441.830 / 1.7990.067 / 0.05946.48
internal tooth1-1/41.251.325 / 1.2751.975 / 1.9210.067 / 0.05950.16
external tooth#20.0860.095 / 0.0860.189 / 0.1770.013 / 0.0104.80
external tooth#30.0990.109 / 0.1020.235 / 0.2200.016 / 0.0105.97
external tooth#40.1120.123 / 0.1150.260 / 0.2450.018 / 0.0126.60
external tooth#50.1250.136 / 0.1290.285 / 0.2700.020 / 0.0147.24
external tooth#60.1380.150 / 0.1410.320 / 0.3050.022 / 0.0168.13
external tooth#80.1640.176 / 0.1680.381 / 0.3650.023 / 0.0189.68
external tooth#100.190.204 / 0.1950.410 / 0.3950.024 / 0.01810.41
external tooth#120.2160.231 / 0.2210.475 / 0.4600.027 / 0.02012.06
external tooth1/40.250.267 / 0.2560.510 / 0.4940.028 / 0.02312.95
external tooth5/160.3120.332 / 0.3200.610 / 0.5880.034 / 0.02815.49
external tooth3/80.3750.398 / 0.3840.694 / 0.6700.040 / 0.03217.63
external tooth7/160.4380.464 / 0.4480.760 / 0.7400.040 / 0.03219.30
external tooth1/20.50.530 / 0.5130.900 / 0.8800.045 / 0.03722.86
external tooth9/160.5630.596 / 0.5760.985 / 0.9600.045 / 0.03725.02
external tooth5/80.6250.663 / 0.6411.070 / 1.0450.050 / 0.04227.18
external tooth3/40.750.795 / 0.7681.260 / 1.2200.055 / 0.04732.00
external tooth7/80.8750.927 / 0.8971.410 / 1.3800.060 / 0.05235.81
external tooth11.1.060 / 1.0251.620 / 1.5900.067 / 0.05941.15

Mating features

Drawn at the exact size. Open press, slide, run and socket features by your process's clearance (tolerances by process); leave designed gaps and clamp fits as drawn.

featureexactmates withfitfiles
bore (ring envelope)ID min (in): #4 .115 internal / .115 external, #6 .141 / .141, #8 .168 / .168, #10 .195 / .195, 1/4 .256 / .256, 5/16 .320 / .320, 3/8 .384 / .384, 1/2 .512 / .513, 5/8 .640 / .641, 3/4 .769 / .768screw of the same nominal size (the bore is the smaller of the ID limits)slidetooth-lock-washer-*
outsideOD max: see the table (e.g. #8 .340 internal / .381 external; 1/4 .478 / .510 in)counterbore or recess at least the washer OD; bearing face under the screw head or nutdesignedtooth-lock-washer-*

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

AFT FastenersInternal tooth lock washer (ASME B18.21.1-2009): nominal, ID max / min, OD max / min, thickness max / minwebPublisher's page; dimensions are facts
Tanner BoltInternal tooth lock washers, ASME B18.21.1-2009 (PDF)webMaker datasheet; numbers only
Tanner BoltExternal tooth lock washers, ASME B18.21.1-2009 (PDF)webMaker datasheet; numbers only
Aspen FastenersExternal tooth lockwasher specification (ASME B18.21.1-1999)webDistributor datasheet; numbers only
McMaster-CarrInternal tooth lock washers (free STEP/IGES per part, for your own design use; no redistribution)STEP, IGES, PDFMcMaster-Carr site terms: personal design use, no redistribution verify
McMaster-CarrInternal-external tooth lock washers (free STEP/IGES per part, for your own design use; no redistribution)STEP, IGES, PDFMcMaster-Carr site terms: personal design use, no redistribution verify

Free files

★ Free files 20 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json

tooth-lock-washer-int-no4-envelopeinternal tooth lock washer #4 envelope: ring from ID min 0.115 in (Ø2.92 mm) to OD max 0.270 in (Ø6.86 mm), thickness max 0.018 in (0.46 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-int-no6-envelopeinternal tooth lock washer #6 envelope: ring from ID min 0.141 in (Ø3.58 mm) to OD max 0.295 in (Ø7.49 mm), thickness max 0.022 in (0.56 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-int-no8-envelopeinternal tooth lock washer #8 envelope: ring from ID min 0.168 in (Ø4.27 mm) to OD max 0.340 in (Ø8.64 mm), thickness max 0.023 in (0.58 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-int-no10-envelopeinternal tooth lock washer #10 envelope: ring from ID min 0.195 in (Ø4.95 mm) to OD max 0.381 in (Ø9.68 mm), thickness max 0.024 in (0.61 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-int-1-4-envelopeinternal tooth lock washer 1/4 envelope: ring from ID min 0.256 in (Ø6.50 mm) to OD max 0.478 in (Ø12.14 mm), thickness max 0.028 in (0.71 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-int-5-16-envelopeinternal tooth lock washer 5/16 envelope: ring from ID min 0.320 in (Ø8.13 mm) to OD max 0.610 in (Ø15.49 mm), thickness max 0.034 in (0.86 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-int-3-8-envelopeinternal tooth lock washer 3/8 envelope: ring from ID min 0.384 in (Ø9.75 mm) to OD max 0.692 in (Ø17.58 mm), thickness max 0.040 in (1.02 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-int-1-2-envelopeinternal tooth lock washer 1/2 envelope: ring from ID min 0.512 in (Ø13.00 mm) to OD max 0.900 in (Ø22.86 mm), thickness max 0.045 in (1.14 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-int-5-8-envelopeinternal tooth lock washer 5/8 envelope: ring from ID min 0.640 in (Ø16.26 mm) to OD max 1.071 in (Ø27.20 mm), thickness max 0.050 in (1.27 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-int-3-4-envelopeinternal tooth lock washer 3/4 envelope: ring from ID min 0.769 in (Ø19.53 mm) to OD max 1.245 in (Ø31.62 mm), thickness max 0.055 in (1.40 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-ext-no4-envelopeexternal tooth lock washer #4 envelope: ring from ID min 0.115 in (Ø2.92 mm) to OD max 0.260 in (Ø6.60 mm), thickness max 0.018 in (0.46 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-ext-no6-envelopeexternal tooth lock washer #6 envelope: ring from ID min 0.141 in (Ø3.58 mm) to OD max 0.320 in (Ø8.13 mm), thickness max 0.022 in (0.56 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-ext-no8-envelopeexternal tooth lock washer #8 envelope: ring from ID min 0.168 in (Ø4.27 mm) to OD max 0.381 in (Ø9.68 mm), thickness max 0.023 in (0.58 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-ext-no10-envelopeexternal tooth lock washer #10 envelope: ring from ID min 0.195 in (Ø4.95 mm) to OD max 0.410 in (Ø10.41 mm), thickness max 0.024 in (0.61 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-ext-1-4-envelopeexternal tooth lock washer 1/4 envelope: ring from ID min 0.256 in (Ø6.50 mm) to OD max 0.510 in (Ø12.95 mm), thickness max 0.028 in (0.71 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-ext-5-16-envelopeexternal tooth lock washer 5/16 envelope: ring from ID min 0.320 in (Ø8.13 mm) to OD max 0.610 in (Ø15.49 mm), thickness max 0.034 in (0.86 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-ext-3-8-envelopeexternal tooth lock washer 3/8 envelope: ring from ID min 0.384 in (Ø9.75 mm) to OD max 0.694 in (Ø17.63 mm), thickness max 0.040 in (1.02 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-ext-1-2-envelopeexternal tooth lock washer 1/2 envelope: ring from ID min 0.513 in (Ø13.03 mm) to OD max 0.900 in (Ø22.86 mm), thickness max 0.045 in (1.14 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-ext-5-8-envelopeexternal tooth lock washer 5/8 envelope: ring from ID min 0.641 in (Ø16.28 mm) to OD max 1.070 in (Ø27.18 mm), thickness max 0.050 in (1.27 mm); teeth and their twist are not modelledSTEP · STL
tooth-lock-washer-ext-3-4-envelopeexternal tooth lock washer 3/4 envelope: ring from ID min 0.768 in (Ø19.51 mm) to OD max 1.260 in (Ø32.00 mm), thickness max 0.055 in (1.40 mm); teeth and their twist are not modelledSTEP · STL
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Plain text: sheet.txt · JSON: /api/geometry?object=tooth-lock-washers-inch-asme-b18-21-1

Tooth lock washers, inch (ASME B18.21.1): internal and external tooth star washers, #2 to 1 in, ID, OD, thickness + ring envelopes, isometric render of a generated part
Render of tooth-lock-washer-ext-no4-envelope from the free STEP; not to scale.

Fits with

Serrated (tooth) lock washers, DIN 6798 forms A, J, V: M1.6–M30 bore, outside diameter, thickness, number of teeth58 sizes★ sheet
OD
Split lock washers, inch (ASME B18.21.1): regular and high-collar spring washer ID, OD, thickness, width, #2 to 2 in41 sizes★ sheet
Spring lock washers, DIN 127 B (split washers, rectangular section): M2–M100 bore, outside diameter, width, thickness, free height34 sizes★ sheet
Flat washers, inch: SAE and USS, 1/4 to 3/4 in (ASME B18.21.1 Type A), isometric render of a generated part
Flat washers, inch: SAE and USS, 1/4 to 3/4 in (ASME B18.21.1 Type A)14 sizes★ 14 files
Plain washers, inch Type B (narrow, regular, wide): #0 to 3 in ID, OD, thickness + 12 washer files, isometric render of a generated part
Plain washers, inch Type B (narrow, regular, wide): #0 to 3 in ID, OD, thickness + 12 washer files63.5×63.5×4.1 mm★ 12 files
Imperial machine screws: #4-40, #6-32, #8-32, 1/4-20, isometric render of a generated part
Imperial machine screws: #4-40, #6-32, #8-32, 1/4-204 sizes★ 18 files
Socket head cap screws, inch: #10-24, #10-32, 5/16-18, 3/8-16, 1/2-13 (ASME B18.3), isometric render of a generated part
Socket head cap screws, inch: #10-24, #10-32, 5/16-18, 3/8-16, 1/2-13 (ASME B18.3)5 sizes★ 25 files

Questions

What is the OD of a 1/4 external tooth lock washer?

0.510 in max (0.494 min), ID 0.267 / 0.256 in, thickness 0.028 / 0.023 in (Tanner and Aspen, ASME B18.21.1).

What is the difference between an internal and external tooth washer?

Teeth on the bore (internal) or on the outside (external); the internal form has a smaller OD, e.g. 0.478 vs 0.510 in for 1/4 (same ID and thickness).

How many teeth does a #10 star washer have?

Not printed in the sources read here.