Custom Machined Standoffs

When the Catalogue Size Doesn't Exist

Standoffs and pillars set the spacing between boards, panels and plates. Off-the-shelf ranges only come in fixed threads and lengths — so the moment you need an odd length, a non-standard thread, or a specific material, you're stuck. That's exactly when a machined standoff makes sense: we turn it to the precise length and thread your assembly needs, with clean full threads on both ends and consistent length across the batch.

Where the Catalogue Stops — and Where a Machined Standoff Starts

Most standoffs should be bought, not machined. Electronics and fastener stockists list thousands of fixed lengths in brass, steel and nylon for pence each, next day. We only make sense where their lists stop:

What you need	In the catalogue?	Machined by EKINSUN
Standard thread, standard length — M3 × 10 hex brass female-female	Buy it there. Pence each, next-day delivery.	Not worth machining one.
A length between two catalogue steps — 22.6 mm, 37.5 mm	Fixed steps only. One UK stockist turns nylon pillars to any length, but with a 100-piece minimum.	Any length, from 1 piece, in metal or plastic, held to ±0.05 mm.
A different thread on each end — M3 female / M4 male, #6-32 / M3	Rarely listed; one stockist charges +15 % per special feature on a 100-piece minimum.	Quoted as one part. Mixed metric and inch ends are routine.
A long metal standoff — over 60 mm	Catalogue hex ranges in M3 reach about 60 mm (one UK catalogue lists M3 × 60 × 5.5 mm); beyond that, mostly nylon.	Turned from bar up to about 250 mm, round or hex, stepped if a long thin body needs stiffening.
Non-standard across-flats, a shoulder or step, a cross-hole, a slot	Not listed.	Machined as drawn.
A material outside the range — 316 stainless, titanium, a specific alloy	Not listed. (PEEK and POM standoffs are catalogue items; buy those.)	Machined to order from certified bar.
Electrical insulator standoffs for busbars or switchgear — DMC, porcelain, epoxy, kV-rated	A moulded, voltage-rated product: buy from a switchgear supplier.	We do not make these. We machine low-voltage isolation standoffs in Delrin, nylon, PTFE or PEEK only.

If a catalogue standoff fits, buy the catalogue standoff. Send us the one that does not exist.

Custom Standoff Specifications

Attribute	Capability
Materials	Aluminium, brass, stainless, steel, Delrin/nylon/PTFE
Configurations	Male-female, female-female, male-male / stud
Threads	Metric (M2+) & imperial (UNC/UNF); custom pitches
Profile	Hex (wrench grip) or round
Length	Any, held tight and consistent across batch
Finish	As-machined, anodize, plate, passivate

The same capability with numbers on it. Catalogue columns are what UK stockists list (ranges vary by supplier); the last column is what we hold as normal practice.

Thread	Typical hex across-flats	Typical catalogue lengths	We machine
M2 / M2.5	4 / 5 mm	3–30 mm	3–60 mm, any value
M3	5 or 5.5 mm	5–60 mm in steps (one catalogue lists 5, 10, 12, 15, 20, 40, 60)	4–150 mm, any value
M4	7 mm	5–80 mm	5–200 mm
M5 / M6	8 / 10 mm	10–100 mm	8–250 mm
#4-40 / #6-32	3/16" / 1/4"	1/8"–2"	any metric or inch length
#8-32 / 10-32 / 1/4"-20	1/4"–3/8"	1/4"–3"	any
Length tolerance	Catalogue: typically ±0.2–0.3 mm		±0.05 mm, one setting per batch, so every standoff in the bag is the same length
Threads / flats / faces	—		6H / 6g threads; across-flats to h11; end faces square to the axis within 0.05 mm

Standoff Configurations — Which to Choose

Standoffs are grouped by the threads on each end. The right one depends on what bolts to what:

Configuration	Ends	Best for
Female-female	Threaded bore both ends	Screw in from each side; the general-purpose spacer-with-threads
Male-female	Stud one end, bore the other	Stacking PCBs/panels — each stud screws into the next, fewer fasteners
Male-male / stud	Threaded stud both ends	Joining two female-threaded parts

Each comes hex (wrench grip for torque) or round (tight or decorative spaces), plus shouldered/stepped pillars. Thread sizes: imperial #2-56, #4-40, #6-32, #8-32, 10-32, 1/4"-20 and up; metric M2, M2.5, M3, M4 and up — including non-standard pitches you can't buy off the shelf. For electrical isolation we also machine plastic (Delrin, nylon, PTFE) standoffs.

Material Choice

6061 aluminium is light and anodizable; brass is the classic conductive choice for electronics; 304 stainless resists corrosion (316 for marine); steel carries load. For electrical isolation we machine Delrin, nylon or PTFE. Threads are cut clean and gauged so they run smoothly both ends — see CNC turning.

The same choice as a table — density, whether the part conducts (a grounded stack needs it, an isolated one must not), how it lives outdoors, and a relative cost with brass as 1.0:

Material	Density g/cm³	Conducts?	Corrosion	Rel. cost	Note
Brass CW614N (CZ121), nickel-plated	8.5	Yes	Good indoors; plate for contact faces	1.0	The default electronics standoff
6061-T6 aluminium	2.70	Yes — but an anodised surface insulates	Anodise for wear and appearance	0.9	Lightest metal; specify bare faces where you need ground continuity
303 / 304 stainless	7.9	Yes (poorly)	Excellent	1.6	Stainless screw in stainless standoff galls — specify 303 or a plated screw
Free-cutting steel EN1A (230M07), zinc-plated	7.85	Yes	Plating only	0.8	Strongest for the money
Delrin / POM	1.41	No	Excellent	0.9	Insulating, dimensionally stable, machines cleanly
Nylon 66	1.14	No	Absorbs moisture	0.8	Insulating; length grows slightly when wet
PTFE	2.20	No	Chemically inert	2.0	Soft — not for structural load
7075-T6	2.81	Yes	Poor unless anodised	1.4	Rarely justified in a standoff — 6061 does the job

Standoff Weight & Material Cost — Compare Live

Standoff material sets weight, cost and how the part behaves electrically and in corrosion. Aluminum and nylon keep a stack light and can insulate; brass and stainless add strength and durability. Enter the outer diameter, thread-bore and length of a round female standoff for a close weight and relative-cost comparison across materials:

Quantity, Lead Time and What Drives the Price

The first standoff pays for the set-up: bar loaded, program written, threads gauged. Pieces two to ten pay almost only for material and machine time, so the unit price falls fastest there; past a hundred the curve is nearly flat. That is why we quote every enquiry at more than one quantity.

Quantity	Production lead time	Then shipping
1 to a few dozen	5 working days (rush: 3 working days at +30–50 %)	5–7 working days by DHL or FedEx to the UK, EU and US. DDP — duty and VAT paid — on request; GBP quotes and invoices for UK buyers.
50–500	15 working days
500+	15–25 working days

Standoffs We Machine Most Often — by Assembly

Assembly	Why the catalogue length fails	What we machine
1U / 2U rack-mount and server enclosures	The height left after panel, base plate and board thickness lands between two catalogue steps; an imperial chassis meets a metric board	Custom-length brass or aluminium, M3 / M4 / #6-32, mixed ends, ±0.05 mm
Stacked boards and power modules	A tall capacitor or heatsink dictates an odd stack height	Long female-female or male-female pillars, stepped where a long thin body needs stiffness
Panels and housings — see also front panels and rack ears	An offset between a plate and a wall that no catalogue foresaw	Shouldered or stepped standoffs, cross-holes and slots as drawn
Sensor and instrument mounts	Isolation and a specific stand-off distance in one part	Delrin, PEEK or 303 stainless, any length

A female-to-female hex standoff in stainless at a length the catalogue skips is cut the same way as a coupling nut; the 304 stainless coupling nuts page lists M2 to M24 at 10 to 100 mm.

Frequently Asked Questions