Mechanical

Spacer and standoff: three dimensions and you are done

This page opens the DrawSTL spacer template: a parametric cylindrical spacer or standoff that sets the distance between two parts, sized in millimetres and downloaded as a print-ready STL. Three values are all it takes: outer diameter, inner diameter and length. Set the inner diameter to zero for a solid disc.

The edge chamfer value puts a 45 degree break on the top and bottom edge, and it stays inside the size you typed. The template also watches the wall: an inner diameter that would leave less than 0.8 mm of wall is clamped, and the panel reports the value used.

Open in editor See the sizes

Free, no sign-up. Change the sizes in millimetres and download the STL.

Ready-made variants

Each variant is the same template with different settings. Follow the link and the editor opens with those values.

M3 washer, 8 mm outside

Outer diameter: 8 mm · Inner diameter: 3.4 mm · Length: 1 mm +1
Open this variant: M3 washer, 8 mm outside
M8 standoff, 10 mm long

Outer diameter: 15 mm · Inner diameter: 8.4 mm · Length: 10 mm +1
Open this variant: M8 standoff, 10 mm long
Thick sleeve, 30/20 mm, 25 mm long

Outer diameter: 30 mm · Inner diameter: 20 mm · Length: 25 mm +1
Open this variant: Thick sleeve, 30/20 mm, 25 mm long
Solid disc, 40 mm diameter

Outer diameter: 40 mm · Inner diameter: 0 mm · Length: 3 mm +1
Open this variant: Solid disc, 40 mm diameter

Adjustable sizes

These values are edited in the editor's template panel. A number outside the range is clamped to the nearest limit automatically.

Size	Range	Default
Dimensions
Outer diameter	4–120 mm	15 mm
Inner diameter	0–110 mm	10 mm
Length	1–80 mm	1 mm
Edge chamfer	0–3 mm	0 mm

What it is used for

Lifting a circuit board off its enclosure as a PCB standoff
A washer that spreads the load under a screw head
Taking up side play on a wheel, pulley or gear axle
Levelling shelves, panels and feet
A short sleeve that forms a sliding surface on a shaft

Printing tips

Orientation: The spacer sits flat on the bed with the hole axis vertical. No rotation needed, and the layers run perpendicular to the axis.
Layer height: 0.16 mm. Use 0.1-0.12 mm for thin washers only 1-2 mm long, and 0.2 mm for sleeves over 20 mm.
Infill: The wall usually comes from perimeters alone; pick 50% or more, and go solid above a 5 mm wall.
Supports: None. The outer surface is vertical and the chamfers are 45 degrees.
Material: PETG resists crushing under a screw head; PLA suits insulating, dimensionally stable spacers. Use TPU when you want vibration damping.

Tips

Make the inner diameter 0.4-0.5 mm larger than the screw shank, otherwise the spacer binds on the thread.
Add a brim for slim sleeves that are taller than they are wide.
If you need many identical spacers, duplicate the part in the editor and print them all in one go.

Wall thickness and the 0.8 mm limit

The wall is half the difference between outer and inner diameter, so 12 mm outer with 8 mm inner gives a 2 mm wall. In FDM printing anything below 0.8 mm drops to a single extrusion width and snaps easily, which is why the inner diameter is clamped.

For load-bearing spacers, 1.5 to 2.5 mm of wall is far safer. If the point is to spread a screw head's pressure, pick an outer diameter at least one and a half times the head diameter, or the washer hides under the head and does nothing.

0.8-1 mm wall: filler and spacing duty only
1.5-2.5 mm wall: under-screw washers and general use
3 mm and up: load-bearing sleeves and sliding surfaces
Inner diameter 0: a solid disc for pads or blanking caps

Spacer, standoff or washer

One template covers all three jobs, and the difference comes from the ratio of length to wall. Parts 1 to 3 mm long behave as washers and spread the screw head's load. Parts 5 to 20 mm long are standoffs that hold a fixed gap between two surfaces.

Thick-walled parts whose length approaches their diameter act like plain bearings. With layers perpendicular to the axis, a turning shaft rubs across layer edges, so for a bearing that runs continuously the bushing or shaft support template is a better start.

Frequently asked questions

What inner diameter should I use for my screw?

Add 0.4-0.5 mm to the screw shank. In practice 4.4 mm works for M4 and 8.4 mm for M8.

Why did my inner diameter get smaller?

It is clamped so the wall never drops below 0.8 mm. Increase the outer diameter if you need a larger hole.

Does the chamfer make the part larger?

No. The chamfer is built inside the outer diameter and length you typed, so the envelope stays the same.

Can I use it for vibration damping?

Print it in TPU and yes. Flexible spacers under motor and fan feet cut vibration noticeably; keep the wall at 2 mm or more.

Similar templates

Set the sizes to fit your part

Open the template in the editor, enter your values and download a print-ready STL. No account needed.

Open in editor

Ready-made variants

M3 washer, 8 mm outside

M8 standoff, 10 mm long

Thick sleeve, 30/20 mm, 25 mm long

Solid disc, 40 mm diameter