Part Type
Custom Machined Aluminum Spacers & Standoffs
For the spacer the catalog never has
This page is for custom aluminum spacers and standoff spacers machined to your print, not the common hex hardware a distributor stocks. If you need an odd length, a specific OD to clear a bearing or connector, a non-standard thread, or a material the catalog skips, a real person quotes it and a number comes back in 24-48 hours. Send a STEP and PDF through the quote form.
Updated June 2026
When the catalog part already exists
Be honest with yourself first. If you need plain M3 or 1/4 in round or hex standoffs in common lengths, a distributor is cheaper and ships tomorrow, and there is no reason to have them turned from bar. This page is for the case where the catalog part does not exist: the length falls between the stock steps, the OD has to clear a specific connector or bearing race, the threads are mixed metric and imperial or a class the off-the-shelf part never offers, or the material is one stock spacers simply do not come in.
Those are the parts that get turned one at a time or in small batches, machined to the print instead of pulled from a bin. From a single replacement up through production runs, there is no minimum order, and the team will flag a design that a stock part would cover before you spend money on a custom one.
Types and how length drives the fit
Round and hex spacers, threaded standoffs (tapped through, blind, or male-female), plain slip spacers with a clearance ID, and board or PCB standoffs all start the same way: a bar turned to an OD, faced to length, then bored or tapped. Hex flats get milled when you need a wrench grip. The variety lives in the details, and length is usually the detail that matters most.
On an unthreaded slip spacer, length sets the stack-up and the preload once the screw is torqued, so a sloppy length means a loose joint or a bottomed-out screw. On a board standoff, length sets the gap between PCBs and the clearance under tall components. Call out length with a real tolerance: ±0.005 in is routine and cheap, and ±0.001 in is available on the faces that set a critical gap. Both ends should be faced square to the bore so the spacer seats flat instead of cocking under load.
ID, OD, concentricity, and threads
The ID is the screw clearance or the bore that fits a shoulder. State whether it is a clearance hole or a slip fit over a known shaft, and give the fit you want rather than a bare number. OD matters when the spacer has to fit inside a counterbore or clear a neighboring part, so dimension it where the fit is real. Concentricity between ID and OD keeps the part from walking off center; if it locates anything, call out a runout figure instead of leaving it to chance.
Threads are where standoffs overlap custom fasteners, and a clear callout prevents the common mistakes. Give the size, pitch, and class (for example M5x0.8 6H, or 1/4-20 UNC 2B), note whether a tapped hole is through or blind, and give the usable thread depth on blind holes so the mating screw does not bottom out. For male-female standoffs, spell out which end is the male stud and its engagement length.
Materials and finishes
6061 aluminum is the default: light, easy to cut, and happy to anodize, which makes it the go-to for board standoffs and general spacers. Step up to 7075 when a thin-wall spacer carries real clamp load and 6061 would crush; the 6061 vs 7075 comparison lays out where the jump is worth it. Brass turns beautifully and is the quiet pick for electrical standoffs that need to conduct or solder. Stainless handles wet and outdoor duty, Delrin insulates and will not mar what it touches, and steel earns its place where stiffness per dollar wins.
Anodize is the finish that pulls double duty on aluminum spacers: corrosion resistance plus a color you can use for keying, so a stack of three lengths reads red, blue, and black on the bench instead of getting mixed up. Brass and stainless usually ship bare or passivated, Delrin ships as-machined. Every part is inspected before it ships, so the length, bore, and thread you called out are checked against the print, not assumed.
Questions
Before you send a job.
01 Should I just buy hex standoffs from a distributor instead?
If you need common sizes in stock lengths, yes, a distributor is cheaper and faster, and that is the right call. This page is for the standoff that does not exist on the shelf: an odd length, a special OD or thread, or a material stock parts do not come in. If a quote request would be better served by a catalog part, the team will say so before you commit.
02 How tight can you hold the length on a spacer?
±0.005 in is routine and the most economical, and ±0.001 in is available on the faces that set a critical gap, preload, or board spacing. Tolerance only the dimension that has to be precise and let the rest breathe, since that keeps the price sensible. Both ends are faced square to the bore so the spacer seats flat.
03 How do I call out the thread on a standoff?
Give the size, pitch, and class, such as M5x0.8 6H or 1/4-20 UNC 2B, and note whether each tapped hole is through or blind. On blind holes, state the usable thread depth so the mating screw does not bottom out, and for male-female standoffs, spell out which end is the male stud and its engagement length. Mixed metric and imperial threads on one part are no problem.
04 Can I order a single custom spacer?
Yes. One piece is a normal order and there is no minimum, so a single replacement or a one-off prototype is everyday work. Per-piece pricing drops as quantity rises because setup is spread across the batch, so if a few spares would help, the quote can show both numbers.
05 Can anodize color be used to tell similar spacers apart?
Yes, and it is a smart move on aluminum. Anodize adds corrosion resistance and lets you key lengths or sizes by color, so a set of nearly identical spacers reads red, blue, and black on the bench instead of getting mixed up. Note the color and which parts get which on the print and it is handled.
Related
Where to go next.
CNC Turning
The core process behind round and hex spacers and standoffs.
View →6061 vs 7075 Aluminum
Which aluminum to choose when a spacer carries clamp load.
View →Custom Fasteners
Threaded standoffs and studs cut to your callout.
View →Get a Quote
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