Bolts and nuts are often bought, sold and checked by weight. This chart gives the approximate weight of 100 steel hex bolts from M6 to M24, so you can convert pieces to kilograms, estimate the weight of an order or check goods received. A hex nut weight table follows.
Fully threaded hex bolts (hex screws) to ISO 4017 / DIN 933 in steel. The length is measured from under the head to the end of the bolt.
| Length (mm) | M6 | M8 | M10 | M12 | M16 | M20 | M24 |
|---|---|---|---|---|---|---|---|
| 20 | 0.62 | 1.25 | 2.12 | – | – | – | – |
| 25 | 0.71 | 1.41 | 2.37 | 3.47 | – | – | – |
| 30 | 0.80 | 1.56 | 2.62 | 3.83 | 7.91 | – | – |
| 40 | 0.98 | 1.88 | 3.12 | 4.56 | 9.25 | 16.0 | – |
| 50 | 1.15 | 2.20 | 3.63 | 5.29 | 10.6 | 18.1 | 28.2 |
| 60 | 1.33 | 2.52 | 4.13 | 6.02 | 11.9 | 20.1 | 31.2 |
| 70 | – | 2.84 | 4.63 | 6.75 | 13.2 | 22.2 | 34.2 |
| 80 | – | 3.16 | 5.13 | 7.47 | 14.6 | 24.3 | 37.2 |
| 100 | – | – | 6.14 | 8.93 | 17.2 | 28.5 | 43.2 |
| 120 | – | – | – | 10.4 | 19.9 | 32.6 | 49.2 |
| 150 | – | – | – | – | 23.9 | 38.9 | 58.2 |
Note: approximate values, plus or minus about 5 %. Head sizes are to ISO 4017. DIN 933 bolts in M10 and M12 have a bigger head (17 mm and 19 mm across flats instead of 16 mm and 18 mm), which adds about 0.14 kg (M10) and 0.19 kg (M12) per 100 pieces. A dash means the length is not usual for that diameter.
Each weight is the steel volume of the hexagon head, a six-sided prism with the ISO 4017 width across flats (s) and head height (k), plus the threaded shank, taken as a cylinder of the thread’s pitch diameter, multiplied by the density of steel, 7.85 g/cm³. The pitch diameter is used instead of the smaller stress area because a rolled thread is formed from a blank of about the pitch diameter, so the threaded part holds about the same amount of steel.
The values are approximate, plus or minus about 5 %. Real bolts have chamfers and are made within size tolerances, so a weighed bolt is often 1 to 5 % lighter than the chart.
Hex nuts to ISO 4032 and DIN 934 in steel. The ISO nut is taller than the DIN nut, and in M10 and M12 the DIN nut has the bigger spanner size, so the two weigh differently.
| Size | ISO 4032 (kg per 100) | DIN 934 (kg per 100) |
|---|---|---|
| M6 | 0.26 | 0.25 |
| M8 | 0.56 | 0.54 |
| M10 | 1.04 | 1.17 |
| M12 | 1.59 | 1.73 |
| M16 | 3.82 | 3.36 |
| M20 | 7.27 | 6.46 |
| M24 | 12.5 | 11.0 |
The nut weights are worked out the same way: a hexagonal prism of the across-flats size and the maximum nut height in the standard, minus a hole at the thread’s pitch diameter, at 7.85 g/cm³. They are upper values. Real nuts have chamfered corners and countersunk threads and are made a little under the maximum height, so a weighed nut is often 5 to 10 % lighter.
JMIKS Fasteners supplies hex bolts in SS 304, SS 316 and SS 202, and in mild steel and high tensile grades from 4.6 to 12.9, from M3 to M36 and 1/4″ to 1-1/4″ BSW, in lengths from 6 mm to 250 mm. Matching hex nuts come in self colour, zinc plated and hot dip galvanized finishes.
See all bolts and nuts, our high tensile bolts, the bolt torque chart and the spanner size chart. For stainless steel grades, read SS 304 vs SS 316 vs SS 202 fasteners.
About 19. A fully threaded M12 x 50 steel hex bolt weighs about 53 g, which is 5.29 kg per 100 pieces, so 1 kg holds about 100 ÷ 5.29 = 19 bolts.
No. Grade 4.6, 8.8, 10.9 and 12.9 bolts are all steel with a density of about 7.85 g/cm³, so bolts of the same size and standard weigh the same. The size, thread length, head standard and coating change the weight; the grade does not.
Yes. A partially threaded bolt (DIN 931 / ISO 4014) has a plain shank at full diameter, so it weighs about 1 to 14 % more than a fully threaded bolt of the same size. The longer the plain shank, the bigger the difference.
A little. SS 304 and SS 316 bolts weigh about 1 to 2 % more than steel bolts. Hot dip galvanizing adds roughly 1 to 4 %, more on smaller sizes, and zinc plating adds under 1 %.
The chart is calculated from standard sizes. Real bolts have chamfers, are made within tolerances and may carry a coating, and DIN 933 heads in M10 and M12 are bigger than ISO 4017 heads. A difference of up to about 5 % is normal.
JMIKS Fasteners is a fastener wholesaler and supplier in Nava Odhav, Ahmedabad. Send the size, length, grade, finish and quantity on WhatsApp (+91 90333 11425) or through the enquiry form, or download the catalogue (PDF). We reply within one working day.
Send the size, grade, finish and quantity on WhatsApp. We reply with the rate and stock position within one working day.
