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Hot Forging · Fastener manufacturing process

Hot Forging

Send a drawing, a sample or a photograph. Samples follow within 7 days of the drawing being approved.

Request a quotation One business day for a reply.

Bicycle-Bottle-Cage-Rack-and-Fender-Bolts

Hot Forging is used at Engineering Hardware to make custom bolts, rigging hardware, anchors & concrete fixings to a customer drawing. Forming above the recrystallisation temperature, where the metal flows freely and large sections can be shaped in one operation. The minimum order is 2,000–5,000 pieces and samples follow within 7 days of the drawing being approved.

Forming above the recrystallisation temperature, where the metal flows freely and large sections can be shaped in one operation.

Heating the blank drops the force needed to move the metal by an order of magnitude, which is what makes large diameters and heavy heads practical. The trade-off is dimensional: hot metal contracts as it cools and scales at the surface, so hot-forged parts are made oversize and finished afterwards. It is the normal route for large structural bolts, eye bolts and anchor components that are simply beyond a cold header.

What Hot Forging is the right choice for

  • Large diameters, typically above the practical cold-forming limit
  • Heavy or complex head geometry
  • Materials too hard or too low in ductility to form cold

Where it is the wrong choice

  • Poorer surface finish and looser tolerance than cold forming
  • Scale has to be removed
  • Higher energy cost per part

Parts produced this way

Usually combined with

Hot Forging is rarely the only operation on a part. On most jobs it sits in a sequence with:

Order terms

Minimum order
2,000–5,000 pieces. The exact figure depends on the part: it is set by the tooling the drawing calls for, and is confirmed when the drawing has been reviewed.
Samples
Within 7 days of drawing approval.
Drawing
Preferred, but not required — a sample, photographs or a sketch is enough to start.

What a quotation needs

Nine things, and a drawing settles most of them at once. Where a field is unknown, say so — an assumption stated is better than a blank, and several of these can be recommended rather than specified.

Drawing
A 2D drawing (PDF or DWG) or a 3D model settles almost every other question on this list at once.
Dimensions
Diameter, length, head size and any features — enough to know what is being made.
Tolerance
Tolerance is the single biggest cost driver. Tell us which dimensions are critical and which are not — holding everything tight costs money on features nobody measures.
Material
Carbon steel, alloy steel, stainless, brass, aluminium, titanium — or the application, and we will suggest one.
Strength grade
Property class to ISO 898-1 (8.8, 10.9, 12.9) or stainless class to ISO 3506 (A2-70, A4-80). This decides the material and the heat treatment together.
Thread standard
Metric coarse, metric fine, UNC, UNF, BSW or a pipe thread — and the tolerance class if it is specified.
Surface finish
Zinc, hot-dip galvanised, black oxide, Dacromet, Geomet, nickel, passivation, or plain. Salt-spray hours if you have a requirement.
Quantity
Annual volume and first-order quantity. Volume changes which process is the right one, so it changes the price more than most buyers expect.
Application & environment
What the part holds together, and what it has to survive — temperature, vibration, chemicals, salt. This is what lets us catch a specification that will not work before it is made.

Draw it here

No CAD, no account, nothing to install. Draw the part in your browser, generate a real ISO metric thread from M1 to M100 with the end treatment it needs, dimension it, and export a PDF or a DXF to attach below. Sheets run to two metres for long studs and threaded rod.

Open the drawing builder

Questions

What is the minimum order quantity for a custom part?

Between 2,000 and 5,000 pieces for most parts. The exact figure depends on the part: it is set by the tooling the drawing calls for, and is confirmed when the drawing has been reviewed.

How long does a sample take?

Within 7 days once the drawing has been approved. The drawing stage comes first, and for a part being reverse-engineered from a sample it is where most of the time goes.

Can you make a part without a drawing?

Yes. A physical sample, photographs against a scale, or a dimensioned sketch are all workable starting points. A drawing is produced from whichever of those you have and sent back for approval before anything is made.

When is Hot Forging not the right process?

Poorer surface finish and looser tolerance than cold forming. Scale has to be removed. Higher energy cost per part.

Which fasteners are made by hot forging?

In this catalog: bolt, rigging hardware, anchor & concrete fixing. Whether it is the right process for a particular part depends on the drawing and the quantity.

Parts of this kind we already make

Showing 36 of 39

081 – Swing Bolt — GB/T 77 / ISO 4026 (Series 020) — GB/T 77 / ISO 4026
097 – Lifting Eye Bolt — GB/T 825 / DIN 580 (Series 036) — GB/T 825 / DIN 580
098 – Lifting Eye Bolt — GB/T 825 / DIN 580 (Series 037) — GB/T 825 / DIN 580
118 – Hex Bolt — GB/T 6173 / ISO 8675 (Series 057) — GB/T 6173 / ISO 8675
12-Point Screws – Bolts
12-Point-Screws-Bolts-Applications
Anchor-Bolts-GB-T-799-DIN-529
asme-b18-5-2-unc-carriage-bolt
Bicycle-Brake-Caliper-Mounting-Bolts
Bicycle-Cleat-Fixing-Bolts
Bicycle-Disc-Brake-Rotor-Bolts
Bicycle-Stem-and-Headset-Bolts
Carbon-Steel-Stainless-Eye-Swing-Bolts
Carriage Bolts — DIN 603
category-bolts
Concrete-Coil-Rods-Coil-Nuts-and-Coil-Bolts
Concrete-Formwork-Wedge-Bolts
din-478-square-head-bolt-with-collar
Elevator Bolts
Elevator-Bolts-Applications
Equal-End Stud Bolt — GB – T 901 – DIN 939 (Series 093) — GB – T 901 – DIN 939
Exhaust-U-Bolt-and-Band-Clamps
Eye Bolts — DIN 580
Fitted-Bolts-DIN-609
Foundation-Bolts-L-J
gn-505-4-serrated-t-slot-bolt
Heavy-Duty-Blind-Bolts
Heavy-Hex-Structural-Bolts
Hex Bolts — ISO 4014 / ISO 4017
Hex Bolts — ISO 4014 / ISO 4017 Applications1
Hex Bolts — ISO 4014 / ISO 4017 Detail
Hex Bolts, Grade C — ISO 4016
Hex Flange Bolts — ISO 1665 / DIN 6921
Huck-C50L-Large-Diameter-Lockbolt-Assembly
Huck-C6L-Small-Diameter-Lockbolt-Assembly
Huck-Magna-Grip-Lockbolt-Assembly

These are catalog parts, shown to say what the tooling already covers. A special is quoted from your drawing, not from this list.

Drawing builder

Draw the part, dimension it, and export a PDF or a DXF to attach to the form below.

FASTENER DRAWING

CMD
Fastener drawing builder https://engineeringhardware.com/

Nothing you draw is uploaded until you send it, and the drawing lives in your own browser — export it before you close the tab.

Send the part

A drawing answers most of this at once. If you do not have one, fill in what you know and attach a photograph — samples follow within 7 days of the drawing being approved.

The only field we cannot do without — it is where the quotation goes.
A 2D drawing (PDF or DWG) or a 3D model settles almost every other question on this list at once.
Diameter, length, head size and any features — enough to know what is being made.
Tolerance is the single biggest cost driver. Tell us which dimensions are critical and which are not — holding everything tight costs money on features nobody measures.
Carbon steel, alloy steel, stainless, brass, aluminium, titanium — or the application, and we will suggest one.
Property class to ISO 898-1 (8.8, 10.9, 12.9) or stainless class to ISO 3506 (A2-70, A4-80). This decides the material and the heat treatment together.
Metric coarse, metric fine, UNC, UNF, BSW or a pipe thread — and the tolerance class if it is specified.
Zinc, hot-dip galvanised, black oxide, Dacromet, Geomet, nickel, passivation, or plain. Salt-spray hours if you have a requirement.
Annual volume and first-order quantity. Volume changes which process is the right one, so it changes the price more than most buyers expect.
What the part holds together, and what it has to survive — temperature, vibration, chemicals, salt. This is what lets us catch a specification that will not work before it is made.