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DIN 931 Hex Head Bolts (Partially Threaded)

DIN 931 hexagon head bolts with shank — the partially threaded metric hex bolt, M1.6 to M39 — with the full collected 23-size table: pitch, thread-length bands, head height, across-flats and across-corners geometry, and the Grade A/B tolerance rows.

Last updated: 2026-11

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DIN 931 Hex Head Bolts (Partially Threaded) in an industrial setting
Illustrative image redrawn from real product references — not a photograph of stocked items.

Specifications

DIN 931 is the partially threaded member of the metric hex-bolt pair: an unthreaded shank between the head and the thread run, which lets the bolt act as a shear-controlled pin while the thread does the clamping. Where the joint carries lateral loads, the smooth shank takes the shear without the stress concentrations of a thread root; where the joint is pure clamping, the fully threaded DIN 933 alternative avoids the grip-length limitation. The designation covers M1.6 to M39. On the collected table the geometry splits into Grade A tolerances for the smaller sizes and Grade B for the larger — head height, across-flats and bearing-face rows carry both grades, each with its own minimum values, and the transition happens around M12–M24 depending on the feature. Thread length b grows in three bands (up to 125 mm, 125–200 mm, above 200 mm), so the same bolt size has three tabulated thread lengths — the band your grip length falls into selects the row. Property class, finish and the commercial cut lengths are not part of the collected table: they follow the drawing callout and the quotation, and for strength-class selection the ISO class pages on this site (8.8, 10.9, 12.9) carry the mechanical data. For the fully threaded counterpart see the DIN 933 page; the ISO 4014/4017 pages cover the ISO-aligned equivalents.

Standard DIN 931 — hexagon head bolts with shank (partially threaded thread)
Series M1.6 – M39 (23 sizes tabulated; sizes above M24 printed in parentheses in the source)
Tabulated geometry Per size: pitch P, thread length b in three length bands, chamfer c, transition diameter d a, shank diameter d s, bearing face d w, across-corners e, head height k, wrench reach k 1, fillet r, across-flats s — Grade A and Grade B tolerance rows as printed
Shank form Partially threaded — unthreaded shank in the grip; shear-favorable joint form
Family note Partially threaded counterpart of DIN 933 (fully threaded); ISO-aligned equivalents ISO 4014/4017
Materials / strength Not tabulated by the collected specification — per RFQ (property class and finish per drawing callout)
DIN 931 hex head bolts with shank (partially threaded) - per-size dimensions (M1.6 - M39)All dimensions in millimeters. Attribute labels follow the source: P = thread pitch; b = thread length for three length bands (the source marks the L≤125 band "Ref."); c = chamfer; d a = transition diameter; d s = shank diameter; d w = bearing face diameter; e = width across corners; k = head height; k 1 = wrench-reach minimum; r = fillet radius under the head; s = width across flats. Grade A rows apply to the smaller sizes and Grade B to the larger ones; where a grade row does not cover a size the source prints "-" — reproduced verbatim. The Grade B value rows and the k max row repeat the Grade A row qualifiers ("min", "max") without printing them — reproduced as printed. Materials, property classes and length ranges are not tabulated by the collected specification.
Nominal threadP — Thread Pitchb — thread length, L≤125 (Ref.)b — thread length, 125＜L≤200b — thread length, L＞200c — minc — maxd a — maxd s — max=nominal sized s — min — Grade Ad s — Grade Bd w — min — Grade Ad w — Grade Be — min — Grade Ae — Grade Bk — Nominal Sizek — Grade A — mink — maxk — Grade B — mink 1 — minr — mins — max=nominal sizes — min — Grade As — Grade B
M1.60.359--0.10.2521.61.46-2.4-3.41-1.10.981.22-0.70.13.23.02-
M20.410--0.10.252.621.86-3.2-4.32-1.41.281.52-0.90.143.82-
M2.50.4511--0.10.253.12.52.36-4.1-5.45-1.71.581.82-1.10.154.82-
M30.512--0.150.43.632.86-4.6-6.01-21.882.12-1.30.15.55.32-
(M3.5)0.613--0.150.44.13.53.32-5.1-6.58-2.42.282.52-1.60.165.82-
M40.714--0.150.44.743.82-5.9-7.66-2.82.682.92-1.90.276.78-
M50.81622-0.150.55.754.82-6.9-8.79-3.53.353.65-2.280.287.78-
M611824-0.150.56.865.82-8.9-11.05-43.854.15-2.630.25109.78-
(M7)12026-0.150.57.876.78-9.8-12.12-4.84.654.95-3.190.251110.73-
M81.252228-0.150.69.287.78-11.6-14.38-5.35.155.45-3.540.41312.73-
M101.52632450.150.611.2109.78-15.6-18.9-6.46.226.58-4.280.41716.73-
M121.753036490.150.613.71211.73-17.4-21.1-7.57.327.68-5.050.61918.67-
(M14)23440530.150.615.71413.73-20.5-24.49-8.88.628.98-5.960.62221.67-
M1623844570.20.817.71615.7315.5722.52226.7526.17109.8210.189.716.80.62423.6723.16
(M18)2.54248610.20.820.21817.7317.5725.324.830.1429.5611.511.2811.7211.157.80.62726.6726.16
M202.54652650.20.822.42019.6719.4828.227.733.5332.9512.512.2812.7212.158.50.83029.6729.16
(M22)2.55056690.20.824.42221.6721.483029.535.7235.031413.7814.2213.659.60.83231.6131
M2435460730.20.826.42423.6723.4833.633.239.9839.551514.7815.2214.6510.30.83635.3835
(M27)36066790.20.830.427-26.48-38-45.217--16.6511.7141-40
M303.56672850.20.833.430-29.48-42.7-50.8518.7--18.2812.8146-45
(M33)3.57278910.20.836.433-32.38-46.6-55.3721--20.5814.4150-49
M3647884970.20.839.436-35.38-51.1-60.7922.5--22.0815.5155-53.8
(M39)484901030.3142.439-38.38-55.9-66.4425--24.5817.2160-58.8
DIN 931 hex bolts (partially threaded) — approximate weight (kg/1000 pcs) by length, M4 – M48Weights in kg per 1000 pieces as printed by the source ("Weight in kgs. per 1,000 pcs. unless otherwise specified. All weights are approximations."). Blank cell = the length/size combination is not tabulated by the source. Decimal points are the source's own. Weights are approximations for shipping/planning, not a guarantee.
Length (mm)Weight kg/1000 pcs — M4Weight kg/1000 pcs — M5Weight kg/1000 pcs — M6Weight kg/1000 pcs — M7Weight kg/1000 pcs — M8Weight kg/1000 pcs — M10Weight kg/1000 pcs — M12Weight kg/1000 pcs — M14Weight kg/1000 pcs — M16Weight kg/1000 pcs — M18Weight kg/1000 pcs — M20Weight kg/1000 pcs — M22Weight kg/1000 pcs — M24Weight kg/1000 pcs — M30Weight kg/1000 pcs — M36Weight kg/1000 pcs — M48
253.124.86
303.615.648.0612.7
354.046.429.1313.618.2
404.537.2010.215.120.335.0
457.9811.316.622.238.053.6
508.7612.318.124.241.158.182.0
5513.419.525.843.862.688.1115
6014.421.027.846.967.094.1123
6522.529.850.070.398.8131171219
7024.031.853.174.7105.0139181231281
7533.756.279.1111.0147191243296
8035.759.383.6117.0155200255311392
8562.488.1123.0163210267326410
9065.592.4127.0171220279341428712
9568.696.8133.0179230291356446739
10071.7101.0139.0186240303370464767
110109.0151.02022603274005008231240
120118.0164.02182803514305358801320
130174.02302963744505609201390
140185.024631639848059597514702860
150262336422510630103015503010
160278356446540665108516303160
170376470570700114017103300
180396494600735120017903440
190519630770125018703580
200544660805131019503720
220720870142021104010
240935153022704290
260164024304570
280175025904850
300186027505130
3205410
3405690
  • Row 1 (25): Column alignment note (batch-level, anchored here): the 16 weight columns align one-to-one to the source header sizes (M4, M5, M6, M7, M8, M10, M12, M14, M16, M18, M20, M22, M24, M30, M36, M48); verified against the rendered grid (rowspan/colspan expanded) and the monotone per-size weight progressions, not inferred from the flattened markup alone. The first grid row is a lone "Length" section label, carried as the first-column semantics.

Materials

  • Material, property class and finish specified per RFQ — the collected specification table covers geometry only

Ordering & documentation

Documents

Shipments are backed by Mill Test Certificate (MTC), Dimensional Report, Salt Spray Test Report on request, with full batch traceability from raw material to finished product. Quality management follows the owner-confirmed compliance list: ISO 9001:2015, RoHS, REACH. Exact document sets are confirmed on the order.

Quotation

  • The fastener family (DIN 931 Hex Head Bolts (Partially Threaded)) plus the standard designation from your drawing — DIN / ISO / JIS / ASTM / ANSI, or a drawing for custom parts.
  • Size (diameter and length), thread type (metric or inch), property class or grade, and coating or finish.
  • Quantity per size and your target delivery date.
  • Destination country, and any required documents (for example a mill test certificate) so the quote includes them.

Sample & supply

Minimum order quantity is 1,000–10,000 pieces depending on size. Stock items run 3–7 days. High-strength and custom parts run 15–25 days. Quantities or variants outside the standard range are confirmed at quotation.

Storage & shipping

Parts are packed for export and shipped factory-direct to buyers in Europe, Asia, the Americas and the Middle East. Store fasteners dry and protected until installation, and keep coated parts in their packaging until use; specific packing and preservation requirements can be stated on the order and confirmed at quotation.

Frequently asked questions

When should a partially threaded DIN 931 bolt be used instead of a fully threaded DIN 933 screw?

When the joint sees lateral (shear) load or needs precise grip control. The unthreaded shank has a larger, smoother cross-section than the threaded portion, so it carries shear with less stress concentration and positions the parts without thread play in the joint plane. DIN 933 fully threaded screws are the right choice when clamping length varies, when the full length must engage thread, or when stock flexibility matters more than shear performance. If the shank must not pass through the threaded hole, check the thread length bands in the table against your grip.

What do the Grade A and Grade B rows in the DIN 931 table mean?

Two tolerance classes in the standard: Grade A applies to the smaller sizes with tighter head and across-flats tolerances, Grade B to the larger sizes with wider ones. The table shows each grade's rows as the source prints them, with "-" where a grade does not cover a size and the min/max qualifiers carried from the Grade A rows onto Grade B values. Where the two grades overlap in the mid range, the tolerances differ but the nominal geometry (across-flats, head height) is the same.

What is the MOQ and lead time for this bolt type?

The minimum order quantity is 1,000–10,000 pieces depending on size. Stock items ship in 3–7 days; high-strength and custom parts in 15–25 days. Common diameters in this designation are widely stocked; confirm the exact schedule against quantity and size mix at quotation.

Related knowledge

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What to include in your inquiry

  • ✓ Standard and property class (e.g. DIN 912, ISO 4762, class 8.8) — or a drawing for custom parts.
  • ✓ Sizes, lengths and thread type (metric or inch).
  • ✓ Quantity per size and your target delivery date.
  • ✓ Destination country, plus any coating or finish requirement.
  • ✓ Any documents you need with the shipment (e.g. mill test certificate) so the quote includes them.
  • ✓ Your inquiry goes straight to the factory team by email and gets a reply within 24 hours.
  • ✓ Factory-direct pricing
  • ✓ Standard and custom specifications
  • ✓ Factory-direct export to buyers in Europe, Asia, the Americas and the Middle East
  • ✓ Full fastener family support

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