What is the difference between grade 8.8 and grade 10.9 bolts?

Grade 8.8 has a minimum tensile strength of 800 MPa and yields at 640 MPa; grade 10.9 reaches 1000 MPa tensile and 900 MPa yield. Use 8.8 for general structural work and 10.9 where the connection is highly loaded or pre-tensioned. Never substitute upward without checking — 10.9 is harder and more sensitive to hydrogen embrittlement in plated finishes.

Can you supply bolts to ASTM instead of DIN?

Yes. We supply ASTM A325 and A490 structural bolts and imperial UNC/UNF threads alongside metric DIN and ISO products. Tell us the specification in the enquiry and we quote against it rather than converting on your behalf.

What minimum quantity do you supply bolts in?

Bulk enquiries generally start around 500 kg on a single size, or one tonne across a mixed package. We are not a counter-sales supplier — pricing is built for merchants, fabricators and contractors buying by the tonne.

Do bolts come with mill certificates?

Yes. EN 10204 3.1 mill certificates, mechanical test reports, packing lists and a certificate of origin ship with the consignment so customs and your QA team have what they need on arrival.

Bulk supply · Africa

Bolts & Nuts

We supply hex bolts, set screws and nuts in bulk across Africa — grades 4.8, 8.8, 10.9 and 12.9, M6 to M42, black, zinc plated or hot-dip galvanised, quoted by the tonne with mill certificates.

GRADE 4.8 / 8.8 / 10.9 / 12.9
M6 TO M42 METRIC
GALVANISED OR BLACK

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Also searched as: hex bolts · set screws · hex nuts · structural bolts · high tensile bolts

Bulk hot-dip galvanised grade 8.8 hex bolts and hex nuts spilling from a carton on a workshop bench

What buyers need to know

Specifying bolts & nuts.

Bolts and nuts are the single largest line in most African fastener packages, and the one where specification mistakes are most expensive. A grade 4.8 bolt substituted into a structural connection, or an electroplated bolt sent to a coastal site, fails long before the steel around it does. We quote the grade, the finish and the standard on the line item so your engineer can sign it off before the container is loaded.

Hex head bolts (DIN 931 part-threaded and DIN 933 fully threaded) cover general engineering and structural steelwork. Set screws, cup square (carriage) bolts, plough bolts for earthmoving wear parts, and countersunk socket products are supplied on the same order. Nuts are matched to the bolt grade — grade 8 nuts to 8.8 bolts, grade 10 to 10.9 — because an under-graded nut strips before the bolt reaches proof load.

For structural steel connections in mining and infrastructure we supply high-strength assemblies with the nut and washer already matched, and can pre-kit them per connection so the erection crew is not sorting loose stock on a windy platform. Volume starts around 500 kg on a single line and runs to full container loads on programme work.

Specification

Full specification table.

Bolts & Nuts specification
Standards	DIN 931, DIN 933, ISO 4014, ISO 4017, ASTM A325, ASTM A490
Grades	4.8, 8.8, 10.9, 12.9 · stainless A2-70 (304) and A4-80 (316)
Diameters	M6 to M42 metric · 1/4" to 1-1/2" UNC/UNF on request
Lengths	16 mm to 400 mm standard, longer cut and threaded to order
Finishes	Self colour (black), zinc plated, hot-dip galvanised to ISO 1461, Dacromet
Nut matching	Grade 8 / grade 10 hex nuts, nyloc, flange and dome nuts
Packing	25 kg cartons, 250 kg bulk bags, kitted assembly packs
Documentation	EN 10204 3.1 mill certificates, test reports, certificate of origin

Types we stock and source

Variants on one enquiry.

Hex bolts (DIN 931 / 933)

Part and fully threaded, the general workhorse.

Structural assemblies

High-strength bolt, nut and hardened washer as one set.

Cup square / carriage bolts

Square neck under a dome head for timber and sheet.

Plough bolts

Countersunk with a locking neck for earthmoving wear parts.

Socket cap screws

DIN 912, 12.9 grade, for machine and plant assembly.

Nuts

Hex, nyloc, flange, dome, and heavy hex to match the bolt grade.

Coating by exposure

Which finish for which African site.

Inland dry: Zinc plated is adequate and keeps the landed cost down.
Coastal within 5 km: Hot-dip galvanised minimum; stainless A4 for fixed marine steelwork.
Mining and process plant: Hot-dip galvanised or Dacromet where chemicals and dust are present.
High UV inland Africa: Coating choice matters less than thickness — specify HDG to ISO 1461.

Full coating selection guide →

Typical order sizes

What a real enquiry looks like.

500 kg mixed M12–M20 galvanised hex bolt and nut sets for a merchant re-stock
3 tonnes of grade 8.8 structural assemblies for a warehouse frame
20 tonnes across four sizes on a six-month call-off for a mine

Questions

Bolts & nuts FAQs.

What is the difference between grade 8.8 and grade 10.9 bolts?: Grade 8.8 has a minimum tensile strength of 800 MPa and yields at 640 MPa; grade 10.9 reaches 1000 MPa tensile and 900 MPa yield. Use 8.8 for general structural work and 10.9 where the connection is highly loaded or pre-tensioned. Never substitute upward without checking — 10.9 is harder and more sensitive to hydrogen embrittlement in plated finishes.
Can you supply bolts to ASTM instead of DIN?: Yes. We supply ASTM A325 and A490 structural bolts and imperial UNC/UNF threads alongside metric DIN and ISO products. Tell us the specification in the enquiry and we quote against it rather than converting on your behalf.
What minimum quantity do you supply bolts in?: Bulk enquiries generally start around 500 kg on a single size, or one tonne across a mixed package. We are not a counter-sales supplier — pricing is built for merchants, fabricators and contractors buying by the tonne.
Do bolts come with mill certificates?: Yes. EN 10204 3.1 mill certificates, mechanical test reports, packing lists and a certificate of origin ship with the consignment so customs and your QA team have what they need on arrival.

Where we ship it

Bolts & Nuts by country.

Usually ordered together.

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