Everything you look up when detailing bolted joints and shafts, in one searchable table: ISO 261 coarse and fine pitches, tap drill and ISO 273 clearance hole sizes, ISO 898-1 stress areas, ISO 4014 and ISO 4032 hex bolt and nut across-flats and heights with the older DIN sizes flagged, ISO 4762 socket cap screw heads and hex keys with counterbores, ISO 7089 washers, DIN 6885 parallel keyways by shaft diameter, and spanner sizes.
What it gives you
- Metric coarse and fine pitches, M1.6 to M64
- Tap drill sizes and fine, medium and coarse clearance holes
- Tensile stress areas for proof and preload calculations
- Hex bolt and nut across-flats and heights, ISO and DIN
- Socket head cap screw head diameter, height, hex key and counterbore
- Plain washer dimensions
- Parallel key sizes and shaft and hub keyway depths by shaft diameter
- Spanner and hex key sizes
Method and standards
Values are the nominal dimensions tabulated in the referenced standards. Tap drills use the D minus P rule for about 75 percent thread engagement, which suits most steels and aluminium; brass, cast iron and stainless may want a slightly larger drill. Keyway widths are toleranced N9 in the shaft and JS9 in the hub for a normal fit.
How to use it
- Pick the table you need from the tabs.
- Type a size, for example M12, or a shaft diameter for keyways, to highlight it.
- Print the table for the workshop wall if you like.
Questions engineers ask
- Why do M10, M12, M14 and M22 have two spanner sizes?
- ISO 4014 and DIN 931 use different across-flats for those sizes: 16, 18, 21 and 34 mm to ISO against 17, 19, 22 and 32 mm to DIN. Both are still sold, so check the bolt before you buy the socket.
- Which tap drill for a fine thread?
- Nominal diameter minus the fine pitch. An M12 x 1.5 thread takes a 10.5 mm drill.
- Where do the stress areas come from?
- ISO 898-1, based on the mean of the pitch and minor diameters. Multiply by the proof stress for the property class to get proof load, which is what the bolt torque calculator uses.
Need a bolted joint designed and checked properly, with preload, joint stiffness and slip margins in a calculation pack? Forgepoint provides mechanical design and analysis from Manchester, UK-wide.
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