Bolt, nut and washer weight calculator

Q: How much do 1000 M12×50 bolts weigh?

Full thread ISO 4017: about 52.4 kg/1000 pcs; part thread ISO 4014: about 55.6 kg.

Q: How much does an M20×80 bolt set with 1 nut + 2 washers weigh?

About 340 g/set (bolt 241 g, nut 65 g, each washer 17 g).

Q: How much does an M16 nut weigh?

An ISO 4032 M16 nut is about 34.2 g; a DIN 934 M16 nut about 30 g.

Select bolt size, length, thread type and nuts and washers per set to get the weight of one set, total weight and kg/1000 pcs.

Bolt = hexagon head + shank (threaded part at pitch diameter)

Bolt, nut and washer weight calculator

Enter dimensions in mm.

Material

Density (kg/m³)

Approximate weight of plain (black) steel bolts, without coating. Head chamfers are deducted.

How bolt weight is calculated

Bolt head: hexagonal prism (√3/2) × s² × k, minus about 3% for chamfers. s = width across flats, k = head height.
Shank: the threaded part is calculated with the pitch diameter d₂ = d − 0.6495 × P (P = thread pitch), the plain part with d.
Nut: hexagon (√3/2) × s² × m minus the threaded hole.
DIN 125 flat washer: annulus π/4 × (d₂² − d₁²) × h.

ISO and DIN head sizes differ for M10 (16/17), M12 (18/19), M14 (21/22), M22 (34/32); ISO 4032 nuts are taller than DIN 934.

Full-thread ISO 4017 bolt weights (kg/1000 pcs)

Size	L20	L30	L40	L50	L60	L80	L100	L120	L150	Nut ISO 4032	DIN 125 washer
M5	3.95	5.19	6.43	7.67	8.9	11.38	13.85	16.33	20.04	1.32	0.44
M6	6.17	7.93	9.7	11.46	13.23	16.76	20.29	23.82	29.11	2.37	1.02
M8	12.28	15.46	18.65	21.83	25.02	31.39	37.76	44.13	53.69	5.1	1.83
M10	20.85	25.87	30.89	35.92	40.94	50.98	61.03	71.08	86.14	9.38	3.57
M12	30.58	37.85	45.13	52.4	59.68	74.23	88.78	103.34	125.16	14.27	6.27
M14	–	55.43	65.37	75.32	85.27	105.16	125.05	144.94	174.78	22.96	8.62
M16	–	77.96	91.28	104.61	117.93	144.58	171.23	197.88	237.85	34.18	11.3
M18	–	104.89	121.42	137.96	154.49	187.56	220.63	253.7	303.3	46.7	14.7
M20	–	136.65	157.47	178.28	199.1	240.74	282.38	324.02	386.48	64.95	17.16
M22	–	–	209.12	234.71	260.31	311.51	362.7	413.9	490.69	92.13	18.35
M24	–	–	248.12	278.1	308.08	368.04	428	487.96	577.9	111.71	32.33
M27	–	–	–	381.91	420.6	497.99	575.37	652.76	768.83	160.86	42.32
M30	–	–	–	497.92	545.32	640.11	734.91	829.71	971.9	221.14	53.64
M33	–	–	–	637.25	695.46	811.88	928.3	1 044.72	1 219.34	286.57	75.34
M36	–	–	–	–	861.55	999.12	1 136.69	1 274.27	1 480.63	379.65	92.08

Frequently asked questions

How much do 1000 M12×50 bolts weigh?

Full thread ISO 4017: about 52.4 kg/1000 pcs; part thread ISO 4014: about 55.6 kg.

How much does an M20×80 bolt set with 1 nut + 2 washers weigh?

About 340 g/set (bolt 241 g, nut 65 g, each washer 17 g).

How much does an M16 nut weigh?

An ISO 4032 M16 nut is about 34.2 g; a DIN 934 M16 nut about 30 g.

What is the difference between DIN 933 and DIN 931?

DIN 933 (ISO 4017) is a fully threaded bolt; DIN 931 (ISO 4014) is part threaded, with a plain shank near the head, so it is slightly heavier for the same length.