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Allen Key Bolt Size

Allen Key Bolt Size



What is an Allen Key Bolt Size?


Allen bolt also called hex key or allen key. Allen key screw have six sided tool designed to fit into the socket hex of an allen bolt. Allen hex bolt normally made of hardened steel and are available in L shaped and straight forms. 5mm allen key bolt used to loosen or tighten allen screws and allen bolts that have matching hex sockets in their heads.


Allen Key Bolt Size Chart in Inches


Metric Allen Key Bolt Size Hex Key Size
M64 1.811
M56 1.614
M52 1.417
M48 1.417
M45 1.260
M42 1.260
M39 1.063
M36 1.063
M33 0.945
M30 0.866
M27 0.748
M24 0.748
M22 0.669
M18 0.551
M16 0.551
M14 0.472
M12 0.394
M10 0.315
M8 0.236
M6 0.197
M5 0.157
M4 0.118
M3 0.098
M2 0.059
M1.6 0.059

Allen Key Bolt Size Chart in mm


Metric Allen Key Bolt Size Hex Key Size
M64 46.0
M56 41.0
M52 36.0
M48 36.0
M45 32.0
M42 32.0
M39 27.0
M36 27.0
M33 24.0
M30 22.0
M24 19.0
M22 17.0
M20 17.0
M18 14.0
M16 14.0
M14 12.0
M12 10.0
M10 8.0
M8 6.0
M6 5.0
M4 3.0
M2 1.5
M1.6 1.5

Ultimate Guide to Allen Key Screw Torque Chart as per DIN 911


Allen Key Bolt Torque Chart


Size Grade 12.9 Grade 10.9 Grade 8.8 Grade 4.8
M48 6860.00 5592.00 4704.00 2254.00
M42 4606.00 3970.00 2744.00 1519.00
M36 2940.00 2453.00 1764.00 980.00
M30 2350.00 1960.00 1225.00 588.00
M24 1176.00 980.00 686.00 314.00
M22 911.00 765.00 539.00 225.00
M20 680.00 569.00 402.00 196.00
M18 480.00 480.00 284.00 137.00
M16 353.00 353.00 247.00 137.00
M14 225.00 225.00 165.00 98.00
M12 160.00 137.00 99.00 60.00
M10 96.00 81.00 58.00 34.00
M8 49.00 41.00 29.00 17.00
M6 20.00 17.00 12.00 7.00
M4 7.80 6.80 5.00 3.00
M2 1.25 1.10 0.85 0.49
M1 0.25 0.22 0.16 0.09

DIN 911 Standard


DIN 911 Standard
Size H L (mm)
M36 140 mm 355
M32 125 mm 315
M27 100 mm 250
M24 90 mm 224
M22 80 mm 200
M19 70 mm 180
M14 56 mm 140
M17 63 mm 160
M14 56 mm 140
M12 45 mm 125
M10 40 mm 112
M8 36 mm 100
M6 32 mm 90
M4 25 mm 70

Everything You Need to Know About Socket Head Cap Screw Allen Key Size


Socket Head Cap Screw Allen Key Size


Socket Cap Screw Key Size (mm)
M16 14
M14 12
M12 10
M10 8
M8 6
M6 5
M5 4
M4 3
M3 2.5
M2 1.5

Socket Button Head Screw Key Size


Socket Button Head Screw Key Size (mm)
M12 8
M10 6
M8 5
M6 4
M5 3
M4 2.5
M3 2

Socket Shoulder Screw Key Size


Socket Shoulder Screw Key Size (mm)
M20 12
M16 10
M12 8
M10 6
M8 5
M6 4
M5 3

Allen Bolt Size vs Allen Key Size


Allen Bolt Size vs Allen Key Size

Wrench and Hex Key Sizes


Diameter Socket Hex
M48 36.00 75.00
M42 32.00 65.00
M36 27.00 55.00
M30 22.00 46.00
M24 19.00 36.00
M22 17.00 32.00
M20 17.00 30.00
M18 14.00 27.00
M16 14.00 24.00
M14 12.00 21.00
M12 10.00 19.00
M10 8.00 17.00
M8 6.00 13.00
M6 5.00 10.00
M4 3.00 7.00
M3 2.50 5.50

Allen Key Sizes for Grub Screws


Size of Thread Diameter Size of Allen Key Wrench
M36 17.0 mm
M30 14.0 mm
M24 12.0 mm
M20 10.0 mm
M16 8.0 mm
M14 6.0 mm
M12 6.0 mm
M10 5.0 mm
M8 4.0 mm
M6 3.0 mm
M4 2.0 mm
M2 0.9 mm

Allen Key Size Chart


Allen Key Size Chart
Screw Size B Shortest Length Allen Key Size A Length
M24 70 mm 19 7.09"
M22 63 mm 17 6.3"
M20 63 mm 17 6.3"
M18 56 mm 14 5.51"
M16 56 mm 14 5.51"
M14 45 mm 12 4.92"
M12 40 mm 10 4.41"
M10 36 mm 8 3.94"
M8 32 mm 6 3.54"
M6 28 mm 5 3.15"
M4 20 mm 3 2.48"
M3 18 mm 2.5 2.2"

When to Use Allen Key Screw?


  • Furniture and fixtures
  • Machinery assembly
  • Equipment repairs
  • Electrical devices

Allen Key Bolt Head Types


  • Button Head
  • Flower Shaped Head
  • Shoulder Screw
  • Cylindrical Head
  • Set Screw
  • Countersunk Head

How to Remove a Stripped 5mm Allen Key Bolt?


How to Remove a Stripped 5mm Allen Key Bolt?

Allen Wrench Sizes


Hex Allen Key Sizes (inch) Width Across Flats (inch) Length of Long Arm and Short Arm (inch)
0.028 0.0275- 0.028 1.219 - 0.219
0.035 0.0345 - 0.035 1.219 - 0.344
0.050 0.049 - 0.050 1.656 - 0.531
1/16 0.0615 - 0.0625 1.75 - 0.562
5/64 0.0771 - 0.0781 1.875 - 0.609
3/32 0.0927 - 0.0937 2 - 0.656
7/64 0.1077 - 0.1093 2.125 - 0.703
1/8 0.1235 - 0.1250 2.25 - 0.75
9/64 0.1391 - 0.1406 2.375 - 0.796
5/32 0.1547 - 0.1562 2.5 - 0.844
3/16 0.1860 - 0.1875 2.75 - 0.938
7/32 0.2172 - 0.2187 3 - 1.031
1/4 0.248 - 0.250 3.25 - 1.125
5/16 0.3110 - 0.3125 3.75 - 1.25
3/8 0.373 - 0.375 4.25 - 1.375
7/16 0.4355 - 0.4375 4.75 - 1.5
1/2 0.04975 - 0.50 5.25 - 1.625
9/16 0.56 - 0.5625 5.75 - 1.75
5/8 0.6225 - 0.625 6.25 - 1.875
3/4 0.747 - 0.75 7.25 - 2.125
7/8 0.872 - 0.875 8.25- 2.375
1 0.049 - 0.050 1.656 - 0.531

Allen Wrench Conversion Chart


SAE Conversion for MM
3/8" 10
5/16" 8
1/4" 7
3/16" 5
5/32" 4
7/64" 3
5/64" 2

Is an Allen Wrench the Same as a Hex Key?


Yes, an Allen wrench is the similar as a hex key. Allen wrench are also known as L wrenche and L key.