The Bolt You Can't Buy Off the Shelf
Sometimes a standard bolt just won't do: you need a length between catalogue sizes, a thread that isn't stocked, a longer unthreaded shank, a shoulder of an exact diameter, or a head that clears a tight space. EKINSUN machines those bolts to your spec — one design at a time, in small to medium quantities.
Send a drawing, or just the bolt you're trying to match and the change you need. We turn it from solid bar and gauge the critical features so it threads and seats correctly.
Custom Bolts We Make
By type
By feature
Hex Heads, Custom Heads & Wrench Flats
The head is how a bolt gets torqued, and it's one of the most common reasons a standard bolt won't fit: the hex is too tall for the clearance, the across-flats size doesn't match the spanner on hand, or the thing you're tightening isn't a bolt at all. We machine the head to suit — or add a gripping feature where there isn't one.
Hex & head options
We cut the hex, or two wrench flats, to whatever across-flats size suits your tool — holding the flats parallel and the corners sharp — and we can put them on parts that don't normally have a head at all, such as a double-ended stud, an adapter or a shaft, so it can actually be torqued. Larger threads (up to about M30 / 1¼") get a proportionally larger hex; tight-clearance jobs get a reduced-height head. Tightening values for standard sizes are in our metric bolt torque chart.
Just need a hex put on a part? Send the part, or a sketch with the across-flats size, and we mill the flats or turn a hex onto it — it doesn't have to be a catalogue bolt.
How We Hold the Critical Features
| Feature | How we hold it |
|---|---|
| Thread | Cut and gauged to metric / UNC / UNF / BSW or your sample's pitch |
| Shoulder & shank diameters | Turned tight, typically ±0.02–0.05 mm where they locate |
| Head & drive | To standard or matched to your original |
| Material / strength | Verified material, heat-treated to grade where required |
Matching an existing bolt? Send the sample — we measure it and rebuild the drawing free. See parts from a sample, or browse obsolete fasteners if it's no longer made.
A note on branded parts. We make a compatible bolt to the original's form, fit and function from what you supply, without implying affiliation with the original manufacturer.
Frequently Asked Questions
Yes — special lengths, non-standard threads, fine/odd pitches, partial threads and custom grip lengths are what we machine. Give us dimensions or a sample and we match it.
Yes — shoulder (stripper) bolts, stepped/multi-diameter bolts and custom unthreaded shanks, turned tight on the shoulder and bearing diameters.
Hex, socket cap, button, countersunk, cheese, slotted, plus custom or security drives and special head profiles — to standard or matched to your sample.
Yes. We mill a hex section or two parallel wrench flats — to your across-flats size — onto studs, adapters, shafts and other parts so they can be tightened with a spanner. Send the part or a sketch with the AF size.
304/316 stainless, titanium, brass, bronze, alloy and tool steels, heat-treated to grade, with black oxide, zinc, passivation or anodising.
No — for standard sizes a distributor is cheaper. We focus on custom, non-standard and special bolts catalogues don't carry, and advise honestly if a standard part would do.
Get Custom Bolts Quoted
Drawing or sample — both accepted. Engineers reply in 24h.
// Qty & price
1 pc
Sample price
Confirm fit before a run
3–10
Unit price drops
Setup cost shared
10+
Best price
All tiers quoted upfront
- →No distributor — you pay the maker directly
- →CAD saved after first order — reorder anytime at lower unit price
support@ekinsun.ltd