While these metric Allen key sizes do exist, they rarely appear in your basic Allen wrench sets. Their purpose is largely to serve specialized applications where size constraints and strength requirements need to be met. These sizes are 1 mm, 1.25 mm, 3.5 mm, 4.5 mm, 5.5 mm, & 7 mm. Less Common SAE Sizes

These dimensions of allen keys can be used to check the accessibility of your bolts were space is limited. For example for an M8 socket head cap screw we need at least 32+8 (head size) = 40mm clearance above the screw for easy accessibility.

Parallel Key and Taper Keys Dimensions and Sizes per. ISO 6885, Part 1, 6886 and 6887 Side fitting square and rectangular keys Square and rectangular taper keys Retaining Snap Ring Stress and Failure Formulas and Calculator Retaining Snap Ring Groove Stress and Failure Formulas and Calculator Torx Head Fastener Basic Dimensions per. ISO 10664

A set of hex key wrenches also called Allen wrenches. Image credit: NC_1/Shutterstock.com. Fasteners come in a wide variety of types, sizes, and materials.

The table below shows metric Allen key sizes and dimensions for corresponding socket cap screws based on Din 912 standards on thread sizes M3-M24. Screw Size (Thread Size) Allen Key Size Required A Length (Inches) A Length (mm) B Shortest Length (mm) RS Hex Key Part No. M3 2.5 2.2 56 18 609-562 M4 3 2.48 63 20 609-556 M5 4 2.76 70 25 734-911

15 New Final Allen Keys Final Author: anirudh Created Date: 20130325072723Z

A complete chart of Allen wrench sizes for both metric & SAE. View all the common hex key sizes that are seen in standard sets at Hand Tool 

valve allen bolt qty key size remark sfa 25 2/8"x3/4" 4 3/16" body + bonnet srtainer 32 2/8"x3/4" 4 3/16" body + bonnet 38slc 2/8"x3/4" 6 3/16" coil housing 38slc 5/16" x 1" 4 7/32" bonnet+ coil cup microsoft word - sizes of allen bolts and key chart used for various valves author: super created date:

Hex Keys & Bits. Alloy Steel. HEX KEYS & BITS, LONG AND SHORT ARM. ASME B18.3-1998. Nominal Key or. Bit and Socket. Size. W. Y. B. C. R. K. Hex Width Across.

Allen wrenches are convenient and helpful. If you aren't sure what size you need, an Allen wrench size chart can be a handy tool to get you on your way.

Metric Standard Parallel Keyway and Key Sizes Shaft Diameter (mm) Keyway (mm) Key (mm)* From To Width (W) Depth (h) Width (W) Depth (T) 6 8 2 1.0 2 2 9 10 3 1.4 3 3 11 12 4 1.8 4 4 13 17 5 2.3 5 5 18 22 6 2.8 6 6 23 30 8 3.3 8 7 31 38 10 3.3 10 8 39 44 12 3.3 12 8 45 50 14 3.8 14 9 51 58 16 4.3 16 10 59 65 18 4.4 18 11 66 75 20 4.9 76 86