Bolted joint configurator
Find the screw a joint needs: length, nut, washers and tools.
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Data
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Screw
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Nut
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Lengths
Parts list
Hole
More information
Length to buy: ISO 4762 M10 × 40
A design guide, based on the standards listed below. For critical joints, check against them or with a specialist.
Partly verified data
We have checked part of this data against reliable sources. The values marked with a have fewer sources than we require: use them as a guide and check them (they may not appear in this view).MechLab Geek accepts no liability for any use of this data or its consequences. Check it before you use it. Legal notice.Spotted a mistake? Let us know.
How this calculator works
Through bolt with a nut: the washer under the head, the parts, the washer and the nut add up, plus 2 pitches that must stick out past the nut. The length offered is the first standard length that reaches that sum.
Into a tapped hole: the parts above the hole add up, plus the engagement you ask for on full thread, plus the 2 pitches of the screw end. Lengths come in steps: the standard length just above is given, and the one just below when it still holds as much as a nut (0.8 d), each with how much full thread it holds, along with how deep to tap and drill the hole.
The head: a countersunk screw is measured with its head, which sits inside the countersink; a counterbore sinks a socket head and shortens the grip length. A screw not threaded up to the head is also checked: its thread must start inside the joint, or it could not be tightened.
Assumptions and limitations
- Metric coarse thread (ISO 262).
- The largest nut height m, washer thickness h and head height k of each standard, so the screw is never short.
- With a nut, the screw sticks out at least 2 pitches (2 P): its end has an incomplete thread (ISO 4753).
- Thread length b as a reference: the plain shank is l − b. The thread run-out (DIN 76-1) is not counted, so leave a margin when the warning is close.
- DIN 74-F countersink: wider than the actual head, so the head goes down until its cone rests and sits a little sunk (about 0.85 mm in M10); a size DIN 74 does not give has a countersink as wide as the head, the head flush. DIN 974-1 counterbores at their flush depth: k max + h max of the washer + 0.4 to 1 mm.
- Tapped hole to DIN 76-1:2016: the usable thread reaches the screw end plus the extra thread requested (none by default), and the drilled hole goes deeper by the chosen run-out (e1 normal or e2 short).
- Not worked out: the loads and the strength of the joint, fine threads. The engagement by material is the recommendation of one reference book (Tabellenbuch Metall), marked to be confirmed.
References
The parts
- ISO 4762:2004 Hexagon socket head cap screws
- DIN 912:1983 Hexagon socket head cap screws
- ISO 4017:2022 Fasteners — Hexagon head screws — Product grades A and B
- DIN 933:1987 Hexagon head screws threaded up to the head; product grades A and B
- DIN 7991:1986 Hexagon socket countersunk head cap screws
- ISO 14579:2011 Hexalobular socket head cap screws
- DIN 7984:2022-03 Hexagon socket head cap screws with low head with reduced loadability
- ISO 7046-1:2011 Countersunk flat head screws (common head style) with type H or type Z cross recess — Product grade A — Part 1: Steel screws of property class 4.8
- DIN 965:1990 Cross recessed countersunk flat head screws
- ISO 14581:2022 Fasteners — Hexalobular socket countersunk flat head screws (common head style) with reduced loadability
- ISO 4032:2012 Hexagon regular nuts (style 1) — Product grades A and B
- DIN 934:1987 Hexagon nuts with metric coarse and fine pitch thread; product grades A and B
- ISO 10511:2012 Prevailing torque type hexagon thin nuts (with non-metallic insert)
- DIN 985:1987 Prevailing torque type hexagon thin nuts with nonmetallic insert
- ISO 7089:2000 Plain washers — Normal series — Product grade A
- DIN 125-1:1990 Washers, product grade A, up to 250 HV, for hexagon head bolts and nuts
- ISO 7092:2000 Plain washers — Small series — Product grade A
- DIN 433-1:1990 Washers, product grade A, up to 250 HV, for cheese head screws
- ISO 7093-1:2000 Plain washers — Large series — Part 1: Product grade A
- DIN 9021:1990 Washers with outside diameter ≈ 3 × nominal thread diameter
The method and the holes
- DIN 974-1:2008 Diameters of counterbores - Manufacturing dimensions - Part 1: Hexagon socket head cap screws and screws with cheese head or pan head
- DIN 74:2003-04 Countersinks for countersunk head screws (form F: hexagon socket countersunk head screws); replaced by DIN 74:2020-01
- DIN 76-1:2016-08 Thread run-outs and thread undercuts - Part 1: For ISO metric threads in accordance with DIN 13-1; replaced by DIN 76-1:2025-10
- DIN 336:2003 Diameters of drills for minor diameters of tapped threads
- ISO 4753:2011 Fasteners — Ends of parts with external ISO metric thread
- ISO 262:1998 ISO general purpose metric screw threads — Selected sizes for screws, bolts and nuts
- ISO 273:1979 Fasteners — Clearance holes for bolts and screws