Aluminum Profile Swivel Caster Connector (Swivel Mounting Block)

Castors and feet · 3 specifications · 3 thread sizes · 4 options in stock

Castors and levelling feet — what the frame stands on. One is for moving, the other is for standing still. The parameters are listed in order of importance: the one at the top decides the most, and no amount of care further down makes up for getting it wrong.

This page lists 4 options: Specification European Standard 2020 / European standard 3030 / European standard 4040, Thread size M6 / M8 / M10. From ¥2.08.

The parts of this item

Figure 1 — Castors are about wheel diameter and mounting holes, feet about the stud and base — both are the four things under the frame

What each parameter decides

Every parameter below shows the real range available on this page, and what goes wrong if you pick it wrong. Work through them in this order and you will not go far wrong.

How to choose, step by step

1. Work out the load per foot — Total machine weight divided by the number of feet, times 1.5. Do not divide by four and call it done — with the centre of gravity off to one side, one foot carries double.
2. Stud thread — M6 / M8 / M10. It has to screw into the extrusion end or a tapped hole in the frame, and it has to be long enough to reach the floor.

How the options on this page are distributed

Figure 2 — how the 4 options on this page are spread across each parameter: the bars on the left show how many options sit in each band, the panel on the right shows the real range of every parameter and how many steps it has.

Variant quick reference

Reading the part numbers

You can order by part number or by selecting the parameters. The part number is fastest, but it does not always encode every parameter — the selector on this page is the authority.

7 common mistakes

1. A castor and a levelling foot do different jobs. A castor moves; a foot stands still and adjusts for level. If it has to be pushed around, castors. If it has to sit solid, feet.
2. Longer stud is not better. A long exposed stud flexes and the machine wobbles. 20–30 mm of adjustment is plenty.
3. The rating is per foot, not for the set. Four 100 kg feet do not carry 400 kg safely — you have no margin left.
4. Four swivel castors go where they like. The usual arrangement is two swivel and two fixed.
5. Check which way the brake lever faces before you bolt it on. A brake you cannot reach with your foot is decoration.
6. Measure before you order. Take the old part off and measure it, or send us a photo with the caliper reading — that beats guessing from a model number every time.
7. Everything here is in millimetres. Where a size is imperial, convert it: 1" = 25.4 mm, 1/4" = 6.35 mm, 3/32" = 2.38 mm.

When to replace it

You do not replace this until it fails — but "still looks usable" and "still reliable" are two different things. Any one of these and it is time:

• Wheel tread worn flat or worn unevenly, so the machine sits at an angle.
• Gritty or notchy wheel rotation — bearing full of swarf or rusted.
• Levelling stud stripped or base deformed, so it will not adjust any more.

Fitting and use

Check before fitting

• Try the thread and length by hand first. If it does not run down smoothly, it is the wrong spec — do not force it with a wrench.
• Measure blind-hole depth. Thread length must be shorter than the hole, otherwise it bottoms out and splits the material.
• For a through hole, check the bolt is long enough to clear the parts and show 2–3 threads.

Tightening

• Run it down by hand until it seats, then use the tool. If it strips by hand, change it — do not force it.
• When several screws hold one part, tighten diagonally in 2–3 stages. Do not take one all the way down first.
• "Seated plus a little" is enough. Brute force stretches the screw or crushes the part. Where a torque is specified, use it.

Staying tight

• Under vibration add a spring washer, a nylon-insert nut or threadlocker. Torque alone will not hold.
• Stainless into stainless galls. Put a little anti-seize on before assembly.
• Where something comes apart repeatedly, use a threaded insert rather than re-cutting the thread in aluminium.

Three things not to do

• Do not treat length as a spec. M6×20 and M6×25 are different parts — one bottoms out, the other does not reach.
• Do not mix coarse and fine pitch. They look alike, bind after two turns, and forcing it destroys the thread.
• Do not reuse a screw that has been stretched, in high-strength joints. Once it has been torqued and released, replace it.

Matching parts

• End caps — when the foot screws straight into the extrusion end
• T-nuts and joining plates — when you would rather not tap the end

Lead time, custom work and shipping

• Stock sizes: dispatched in 1–2 working days, subject to stock
• Custom: non-standard sizes, materials and treatments are possible — send quantity and drawing
• Shipping: from Shenzhen; domestic courier by default, DHL or dedicated line for export
• Volume: quantity pricing available, contact us for a quote

If you cannot find the size you need, or you are not sure which one fits, send us the problem you are solving — what machine it goes on, the dimensions of the part you have, what it has to achieve — and we will match it.