Stainless Steel Washer Weight Calculator
Washer weight matters for more than curiosity. Freight is usually quoted by gross weight, some buyers price small stainless parts by weight rather than piece count, and packing lists need an accurate kilogram figure per carton. Enter your dimensions below and get weight per piece, per 1,000 pcs, and for your full order quantity.
This tool estimates a plain flat washer — a solid ring of constant thickness. It doesn't account for edge chamfers, coatings, or plating, which shave a small amount off the raw geometric weight. For a quote-ready figure, confirm with HUIHUI directly.
The formula
A flat washer is a ring: outer circle minus bore circle, times thickness, times density. This calculator uses exactly this, with no rounding shortcuts in between steps:
d2, d1, s in millimeters · density in g/cm³
Densities used: 304 / A2 stainless = 7.93 g/cm³, 316 / 316L / A4 stainless = 7.98 g/cm³. These are the standard published densities for austenitic stainless in the 300 series and are what we use internally for packing-list weight estimates.
Approx. weight of common DIN 125 flat washers (304 stainless)
| Thread | Bore d1 (mm) | OD d2 (mm) | Thickness s (mm) | Weight per pc (g) |
|---|---|---|---|---|
| M6 | 6.4 | 12 | 1.6 | 1.03 |
| M8 | 8.4 | 16 | 1.6 | 1.85 |
| M10 | 10.5 | 20 | 2.0 | 3.61 |
| M12 | 13 | 24 | 2.5 | 6.34 |
| M16 | 17 | 30 | 3.0 | 11.4 |
| M20 | 21 | 37 | 3.0 | 17.3 |
316 and 316L run about 0.6% heavier than 304 at the same dimensions — the density difference is small enough that most buyers use the 304 figures for both grades when estimating freight. Coating or surface finish (passivation, electropolish) adds no measurable weight. Production tolerances on bore, OD and thickness mean actual parts will vary slightly from any calculated figure; treat these numbers as planning estimates, not a certified weight.
FAQ
How is washer weight calculated?
A flat washer is a ring, so its volume is the outer circle area minus the bore circle area, times thickness: (π/4) × (OD² − bore²) × thickness. Multiply that volume (in mm³, converted to cm³) by the material density — 7.93 g/cm³ for 304, 7.98 g/cm³ for 316 — to get weight in grams. This calculator runs that exact formula on whatever dimensions you enter.
How much does an M8 stainless washer weigh?
A DIN 125 M8 washer (8.4 mm bore, 16 mm OD, 1.6 mm thick) in 304 stainless weighs about 1.85 g per piece, or roughly 1.85 kg per 1,000 pcs. In 316 it's about 0.6% heavier, close enough that most buyers use the same figure for freight estimates.
Are 304 and 316 washers different weights?
Yes, but only slightly. 316 stainless has a density of about 7.98 g/cm³ against 7.93 g/cm³ for 304 — a difference of roughly 0.6%. For the same dimensions, a 316 washer is marginally heavier than a 304 one, but the gap is small enough that it rarely changes a freight quote in any meaningful way.
How do I estimate my shipment weight?
Enter your washer dimensions and order quantity into the calculator above — it multiplies weight per piece by quantity to give total net weight in kilograms. That figure is the washer metal only; for an actual freight quote, add packaging (cartons, pallets, moisture-proof bags) and check with HUIHUI for the gross shipping weight, since packing method affects the final number.
Can HUIHUI confirm exact weights?
Yes. This calculator gives a close estimate for a plain flat washer, but actual weight can shift slightly with production tolerances, chamfered edges, or coatings. Send your drawing or standard/size/material/quantity and we'll confirm the exact per-piece and total weight before you order.
For the underlying dimensions behind these numbers, see the stainless steel washer size chart or the full DIN 125 flat washer size table. More reference tools are on the guides index.
Need an exact weight for a quote or packing list?
Send the standard, M-size, material grade (304 / 316 / 316L), and quantity. We reply with confirmed weight, pricing and lead time within one business day.
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