Fell Marine Bolt Set M8 × 80
A4 stainless, bolt + nut + two washers — box of 20 sets
$46.00
USDStandard shipping $9.00, free over $85. Arrives in 3–6 business days. 30-day returns.
A full set rather than a loose bolt: hex bolt, nyloc nut and two form-A washers, all A4, boxed twenty to a box. Buying the four parts separately is how you end up with an A4 bolt and a zinc nut on the same joint, which corrodes faster than either would alone.
A4 is 316 stainless — the grade with molybdenum in it. It is the one to use within sight of salt water, around a pool, or anywhere road salt gets thrown. Inland and under cover, A2 does the same job for half the money and there is no reason to pay for this.
Working load limits
What this item holds, in the material you are fixing into. Every figure is a working load — the safety factor is already taken out.
Safety factor4:1 — every figure below is the tested mean divided by four.
| Substrate / condition | Working load | Notes |
|---|---|---|
| Steel-to-steel, both plates 6 mm, nut fully engaged | 1,180 lb | Tension. A4-80 has a lower proof stress than an 8.8 carbon bolt of the same size — do not substitute by diameter alone. |
| Steel-to-steel, single shear through the plain shank | 890 lb | Shear. The joint must be arranged so the shank, not the thread, crosses the shear plane. |
| Timber-to-steel, 45 mm timber, washered | 640 lb | Tension. Governed by the timber crushing under the washer, not by the bolt. |
How these were arrived at
Bolt figures derive from the A4-80 property class proof load; the timber figure was measured on the bench rig at 12% moisture content. The nyloc insert is rated for repeated use up to five times before it stops holding torque.
The specification
Everything we know about this item, stated plainly. The same record is printed on the card in the box.
- Composition
- A4-80 (316) austenitic stainless throughout: DIN 931 partially-threaded hex bolt, DIN 985 nyloc nut with a polyamide insert, two DIN 125 form-A washers.
- Dimensions
- M8 × 80 mm bolt, 22 mm thread length, 13 mm across-flats head. Washers 16 mm OD × 1.6 mm.
- Weight
- 41 g per set; 840 g per box of 20.
- Finish & variation
- Mill finish, unpolished. A4 will tea-stain in standing salt water — surface discoloration that wipes off and is not pitting. Genuine pitting only follows prolonged chloride contact without rinsing.
- Made
- Cold-formed and rolled in Taiwan to DIN tolerances, batch-tested for grade on arrival, boxed here in Pennsylvania.
Care
- Rinse with fresh water after salt exposure — that single step is the difference between staining and pitting.
- Use an anti-seize compound on the thread. Stainless against stainless galls, and a galled nut cannot be removed or reused.
- Do not mix with zinc-plated or galvanised parts in a wet joint.
Cautions
- Not stronger than carbon steel. A4-80 is roughly the strength of a grade 5 bolt, not a grade 8 — people substitute stainless expecting an upgrade and get the opposite.
- Not for high-temperature work. Above about 750°F the grade loses its corrosion resistance permanently, even after it cools.
- Not to be run down with an impact driver. Stainless galls under speed and heat; tighten it slowly with a wrench.
Shipping
$9.00 standard, free over $85. 3–6 business days. Full policy
30 DAYS
Returns
Unused and in original packaging. Refunded within 5 business days of reaching us. Full policy
Questions about this product
help@livwellhardware.comEvery message answered within one business day.
