Unifit Metalloys Inc. is a prominent manufacturer & supplier of the best quality screws according to Indian & International standards. This screw weight chart provides approximate weights per 100 of the most frequently ordered screw types (machine screws, hex head screws, socket head cap screws and set screws) for millimetre and inch sizes as well as the weight formula to use to calculate for any size and material combination.
On the shop floor and in the procurement function, screw weight is used daily to convert a piece count into a dispatch weight, to estimate freight cost before an order is made, to cross-check an order delivery with the purchase order and to plan the raw material requirement for a production run. As Unifit Metalloys make screws in stainless steel, alloy steel, carbon steel, duplex steel, super duplex steel, Monel, Hastelloy and Inconel, weight comparison is provided material-wise, as there is an obvious difference in the weight of the same screw size made from different materials.
Unifit Metalloys Inc. is certified with ISO 9001:2015 and is known for manufacturing and exporting several products made of stainless steel, alloy steel, duplex and nickel-alloy fasteners. The company supplies products for industries like oil and gas, power generation, pharmaceuticals, and pulp and paper.
Table of Content
A screw weight table indicates the weights of screws of different dimensions, types, and materials. Most of these tables provide the weight in terms of the weight of 100 pcs. of the particular kind of screws (kg/100 pcs.), facilitating easy estimates of the required weight of the fasteners.
For instance, if the weight of a screw is 0.50 kg for 100 pcs., then the weight of 1000 screws works to be 5.00 kg. But the actual weight can be different due to the variations in the dimensional standard, head shape, thread configuration, grade of material, and manufacturing tolerance.
All weights below are approximate weights in kg/100 pieces (nos.), and this is the industry standard method for quoting the weight of fasteners, allowing you to adjust for any order size by multiplying. The figures are read across the top row of each table and down the left column; when a diameter/length combination is not commercially available, the space is blank. Sizes are given in millimetres (metric, in accordance with IS standards) and are followed by inch/UNC equivalent size, if applicable.
All amounts quoted are estimates for project planning and quotations only, and should you require a certified weight on a confirmed purchase order, please contact our sales team.
To get a rough estimate of the number of screws per kilogram, divide 100 by the weight per chart in kg per 100 screws. For example, if a screw weighs 0.5 kg per 100 screws, 200 screws will weigh approximately 1 kg.
Screw Weight Formula – How Screw Weight Is Calculated?
Every screw weight chart, including the tables below, is built from one underlying formula:
Weight = Volume × Density
The volume depends only on the dimensions of the head, shank and thread of the screw as per the specified IS/DIN/ASME standard and is dependent on the material the screw is to be fabricated in. That's why the weight of the same size screw made of a nickel alloy is different from the weight of a carbon steel screw or a stainless steel screw, and the volume of the screw remains the same, but the density changes.
Worked example — M8 × 40mm Hex Head Screw:
Establishing a reference screw shape from the appropriate standard is vital for comparisons among different materials. The weight of the alternative material can then be calculated using the density ratio:
Material Weight = Reference Weight × (New Material Density ÷ Reference Material Density)
| Material | Density (g/cm³) | Approx. Weight per 100 pcs (kg) |
|---|---|---|
| Carbon/Mild Steel | 7.85 | 18.70 |
| Alloy Steel | 7.85 | 18.70 |
| Duplex Steel (2205) | 7.80 | 18.58 |
| Super Duplex Steel (2507) | 7.80 | 18.58 |
| Stainless Steel 304 / 316 | 8.00 | 19.05 |
| Inconel 625 | 8.44 | 20.10 |
| Monel 400 | 8.80 | 20.96 |
| Hastelloy C276 | 8.89 | 21.17 |
Figures are indicative and have been determined using the density-ratio method to the standard mild-steel baseline. Other sizes are available in our material-wise comparison table, and the density data on our stainless steel, alloy steel and duplex steel pages. (See our material-wise comparison table below for other sizes; and our stainless steel, alloy steel and duplex steel product pages for grade-specific density data.)
Approximate weight in kgs for 100 nos.
| Dia \ Length | 6mm | 8mm | 10mm | 12mm | 16mm | 20mm | 25mm | 30mm | 40mm | 50mm |
|---|---|---|---|---|---|---|---|---|---|---|
| M1.6 | 0.011 | 0.014 | 0.016 | 0.018 | 0.023 | |||||
| M2 | 0.021 | 0.025 | 0.029 | 0.032 | 0.040 | 0.047 | ||||
| M2.5 | 0.036 | 0.042 | 0.048 | 0.054 | 0.066 | 0.078 | ||||
| M3 | 0.060 | 0.069 | 0.078 | 0.087 | 0.104 | 0.122 | 0.144 | 0.166 | 0.210 | 0.254 |
| M4 | 0.111 | 0.126 | 0.141 | 0.157 | 0.188 | 0.219 | 0.258 | 0.296 | 0.380 | 0.457 |
| M5 | 0.206 | 0.220 | 0.255 | 0.280 | 0.330 | 0.378 | 0.440 | 0.502 | 0.625 | 0.750 |
| M6 | 0.356 | 0.392 | 0.427 | 0.498 | 0.569 | 0.656 | 0.745 | 0.920 | 1.090 | |
| M8 | 0.785 | 0.849 | 0.977 | 1.100 | 1.260 | 1.420 | 1.740 | 2.060 | ||
| M10 | 1.460 | 1.660 | 1.860 | 2.110 | 2.360 | 2.860 | 3.360 |
Machine Screws – CSK (Countersunk) Head, as per IS 1365-2005
Approximate weight in kgs for 100 nos.
| Dia \ Length | 6mm | 8mm | 10mm | 12mm | 16mm | 20mm | 25mm | 30mm | 40mm | 50mm |
|---|---|---|---|---|---|---|---|---|---|---|
| M1.6 | 0.009 | 0.011 | 0.013 | |||||||
| M2 | 0.015 | 0.019 | 0.023 | 0.026 | 0.034 | 0.042 | ||||
| M2.5 | 0.026 | 0.032 | 0.038 | 0.044 | 0.056 | 0.068 | 0.083 | 0.098 | ||
| M3 | 0.037 | 0.047 | 0.056 | 0.065 | 0.089 | 0.100 | 0.122 | 0.145 | 0.188 | 0.232 |
| M4 | 0.094 | 0.110 | 0.125 | 0.150 | 0.187 | 0.226 | 0.264 | 0.338 | 0.414 | |
| M5 | 0.183 | 0.208 | 0.260 | 0.307 | 0.370 | 0.431 | 0.555 | 0.680 | ||
| M6 | 0.274 | 0.308 | 0.405 | 0.450 | 0.538 | 0.626 | 0.801 | 0.970 | ||
| M8 | 0.611 | 0.790 | 0.865 | 1.020 | 1.180 | 1.500 | 1.810 | |||
| M10 | 1.350 | 1.450 | 1.700 | 1.950 | 2.450 | 2.950 | ||||
| M12 | 2.180 | 2.550 | 2.920 | 3.650 | 4.380 |
The downloaded PDF includes full charts for Pan Phillips Head, CSK Phillips Head and BSW machine screws up to M20/1", as well as self-tapping screw weights.
The approximate weight of 100 pieces is needed in kg
A weight table for verified Pan/Phillips head machine screws should be inserted here with sizes based on diameter × length as done in the Cheese Head and CSK tables. The primary metric sizes and lengths used by the clients should be present along with the dimensional standard which is applicable.
This information should not be extracted from the PDF only and the table should be in the HTML format for Google to catch it while searching by terms such as "machine screw weight chart" and "Pan Phillips screw weight".
Hex Head Screw Weight Chart (DIN 933)
Approximate weight in kgs for 100 nos. (metric, full thread)
| Dia \ Length | 10mm | 16mm | 20mm | 25mm | 30mm | 40mm | 50mm | 60mm | 80mm | 100mm |
|---|---|---|---|---|---|---|---|---|---|---|
| M4 | 2.10 | 2.41 | 2.80 | 3.19 | 3.96 | 4.73 | 5.50 | |||
| M5 | 3.37 | 3.87 | 4.49 | 5.11 | 6.35 | 7.59 | 8.83 | 11.30 | ||
| M6 | 4.08 | 5.11 | 5.80 | 6.65 | 7.51 | 9.23 | 11.00 | 12.70 | 16.20 | |
| M8 | 15.2 | 19.2 | 21.2 | 23.7 | 26.2 | 31.2 | 36.2 | 41.3 | 51.3 | 61.3 |
| M10 | 27.7 | 31.0 | 34.1 | 37.7 | 44.9 | 52.0 | 58.2 | 73.6 | 88.0 | |
| M12 | 44.0 | 48.0 | 53.0 | 57.9 | 67.9 | 77.9 | 87.8 | 107 | 127 | |
| M16 | 58.3 | 63.5 | 70.2 | 76.9 | 90.2 | 103 | 117 | 144 | 170 | |
| M20 | 105 | 114 | 124 | 134 | 155 | 176 | 196 | 238 | 279 |
The standard followed : DIN 933 and IS 1364. See the downloadable PDF or contact our team for a size-specific chart for BSW/imperial hex screws and lengths over 100mm.
Socket Head Cap Screw Weight Chart
As per IS 2269/2006, ISO 4762 : 2004 — Approximate weight in kgs for 100 nos.
| Dia \ Length | 10mm | 16mm | 20mm | 25mm | 30mm | 40mm | 50mm | 60mm | 80mm | 100mm |
|---|---|---|---|---|---|---|---|---|---|---|
| M3 | 0.088 | 0.116 | 0.136 | 0.161 | 0.186 | |||||
| M4 | 0.180 | 0.225 | 0.265 | 0.315 | 0.365 | 0.465 | ||||
| M5 | 0.270 | 0.345 | 0.401 | 0.478 | 0.555 | 0.709 | 0.863 | |||
| M6 | 0.470 | 0.575 | 0.653 | 0.759 | 0.830 | 1.100 | 1.320 | 1.540 | ||
| M8 | 1.210 | 1.340 | 1.500 | 1.690 | 2.090 | 2.490 | 2.890 | 3.700 | ||
| M10 | 2.090 | 2.290 | 2.540 | 2.790 | 3.290 | 3.930 | 4.570 | 5.850 | 7.120 | |
| M12 | 3.210 | 3.570 | 3.930 | 4.650 | 5.450 | 6.340 | 8.020 | 9.800 | ||
| M16 | 7.130 | 7.780 | 9.100 | 10.60 | 12.20 | 15.40 | 18.60 | |||
| M20 | 12.80 | 15.00 | 17.20 | 19.40 | 24.10 | 29.10 |
Hexagonal Socket Set Screws (Grub Screws, Cup Point) as per IS 6094 (Part 4) / 2006, ISO 4029:2003: Approximate weight in kgs for 100 nos.
| Dia\Length | 4mm | 6mm | 8mm | 10mm | 16mm | 20mm | 25mm |
|---|---|---|---|---|---|---|---|
| M3 | 0.010 | 0.022 | 0.030 | 0.038 | 0.062 | ||
| M4 | 0.023 | 0.038 | 0.053 | 0.068 | 0.113 | 0.140 | |
| M5 | 0.054 | 0.078 | 0.102 | 0.174 | 0.222 | 0.282 | |
| M6 | 0.074 | 0.109 | 0.144 | 0.249 | 0.319 | 0.407 | |
| M8 | 0.188 | 0.251 | 0.440 | 0.566 | 0.724 | ||
| M10 | 0.372 | 0.673 | 0.872 | 1.120 | |||
| M12 | 0.950 | 1.230 | 1.580 |
| Spec \ Length(mm) | 6.5 | 9.5 | 13 | 16 | 19 | 25 | 32 | 38 | 50 |
|---|---|---|---|---|---|---|---|---|---|
| ST2.2 | 0.19 | 0.24 | 0.31 | 0.36 | 0.41 | 0.52 | |||
| ST2.9 | 0.41 | 0.49 | 0.59 | 0.68 | 0.77 | 0.94 | 1.1 | 1.3 | 1.7 |
| ST3.5 | 0.68 | 0.83 | 0.99 | 1.1 | 1.3 | 1.6 | 1.9 | 2.2 | 2.8 |
| ST3.9 | 0.86 | 1.0 | 1.2 | 1.4 | 1.6 | 1.9 | 2.3 | 2.6 | 3.3 |
| ST4.2 | 1.1 | 1.3 | 1.5 | 1.7 | 1.9 | 2.3 | 2.8 | 3.2 | 4.0 |
| ST4.8 | 1.9 | 2.2 | 2.4 | 2.7 | 3.2 | 3.8 | 4.4 | 5.4 | |
| ST5.5 | 2.8 | 3.1 | 3.5 | 4.2 | 5.0 | 5.7 | 7.1 | ||
| ST6.3 | 4.3 | 4.8 | 5.2 | 6.1 | 7.2 | 8.2 | 10.0 |
The table below lists the weight for a reference screw size (M10 hex head screw, DIN 933) for each material family supplied by Unifit Metalloys as screws; for any other screw size in the tables on this page, calculate the weight ratio using the formula.
| Material | Approx. Density (g/cm³) | M10 × 50mm Weight per 100 pcs (kg) |
|---|---|---|
| Carbon Steel | 7.85 | 52.0 |
| Alloy Steel | 7.85 | 52.0 |
| Duplex Steel (UNS S31803) | 7.80 | 51.7 |
| Super Duplex Steel (UNS S32750) | 7.80 | 51.7 |
| Stainless Steel 304 / 316 | 8.00 | 53.0 |
| Inconel 600 / 625 | 8.44–8.47 | 55.9 – 56.1 |
| Monel 400 | 8.80 | 58.3 |
| Hastelloy C276 | 8.89 | 58.9 |
See our product pages for grade-specific density and mechanical properties for Stainless Steel,Alloy Steel,Carbon Steel,Duplex Steel,Super Duplex Steel,Nickel Alloy,Monel,Hastelloy, andInconel product pages
To access our free screw weight chart, contact our team to order a custom weight chart for your particular order for all screw diameters and lengths, metric and imperial, for machine screws, hex screws, socket screws, set screws and self-tapping screws. Request a Customised Weight Chart or download the Screw Weight Chart PDF from our website
Request a Customised Weight Chart or download the Screw Weight Chart PDF from our website.
| Specifciation | Details |
|---|---|
| Dimensions Standards | ASME B18.2.1, B18.3, IS 1364, IS 1365, IS 1366, DIN 933, DIN 912, ISO 4762, ISO 4029 |
| Materials Covered | Carbon Steel, Alloy Steel, Stainless Steel (304/316), Duplex Steel, Super Duplex Steel, Monel, Hastelloy, Inconel |
| Weight Basis | Approximate weight in kgs per 100 nos. |
| Unit System | Metric (mm) with inch/UNC equivalents |
| Certification | Dual Certified as per ASTM & ASME Codes |
Refineries | Oil and Gas Industry | Power Generation | Pharmaceutical Equipment | Pulp & Paper Industry
This will depend on the size of the screw (diameter, length), the type of head and the material the screw is constructed from. A small M3 machine screw can weigh as little as a few grams, while a large M20 hex stainless steel screw has over 100 grams of weight. To get the exact weight of 100 pieces, use the charts above to determine your size.
Weight of screw = Volume × Density. The volume relates to the dimensions of the screw head, shank and thread as per the relevant standard (IS, DIN or ASME) and the density of the material (e.g. stainless steel is denser than mild steel and therefore the same screw size will have a higher weight in stainless steel).
The weight of an M8 × 40mm hex head screw is about 18.70 kg per 100 pieces, carbon steel, and about 19.05 kg per 100 pieces, stainless steel 304/316.
It depends on the size of the screw. An example of this is an M6 × 20mm cheese head machine screw which weighs approximately 0.569kg per 100 machine screws, so 1kg would contain approximately 175 machine screws. To get pieces per kg for any size, divide 100 by the per 100 pcs weight from the above chart and then multiply by 100.
Yes. If the size and type of head are the same, the weight of the screw will vary according to the density of the material. For the same screw size, nickel alloys such as Hastelloy and Monel are heavier than carbon steel and duplex steel, as can be seen in the material comparison table above.
The density of stainless steel (304/316) is approximately 8.00 g/cm³ compared with approximately 7.85 g/cm³ of mild/carbon steel. This implies that a 200mm long stainless steel screw will be just a little heavier than a 200mm long mild steel screw.
Screws and other fasteners are in stock at our stockyard in bulk for a variety of stainless steel, alloy steels, carbon steel, duplex steel and nickel alloys. Call us for a size-by-size weight chart, bulk order quote, or technical assistance in choosing the correct screw material for your project.
Related: Fasteners Manufacturer | Stainless Steel Products | Alloy Steel Products | Duplex Steel Products