Swivel Ball Foot

OEM / ODM Available Free Sample Available ISO 9001:2015 ISO 14001 RoHS REACH

Self-aligning levelling foot with a ball-and-socket joint between stem and pad, keeping the pad flat on the floor when the frame leg is not exactly vertical.

Wholesale Price $0.65 - $6.80 / pc per pc

Material	PA6 nylon / steel / stainless steel pad, zinc-plated steel stem
Alloy Grade	Not applicable
Temper	custom
Section Size	Fits profile ends with M8-M16 thread insert
Slot	M8 / M10 / M12 / M16 stem thread
Length	Stem 40-80 mm; overall height 55-140 mm
Tolerance	±0.3 mm on thread pitch diameter
Surface	Zinc plated stem; moulded or stainless pad
MOQ	200
Lead Time	15-25 days after deposit
Loading Port	Shanghai / Ningbo
Supply Ability	150,000 pcs per month
Payment Terms	T/T 30% deposit + 70% before shipment \| L/C at sight
Trade Terms	FOB \| CIF \| EXW
Certifications	ISO 9001:2015 \| ISO 14001 \| RoHS \| REACH

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Levelling feet · Self-aligning

A swivel ball foot has a ball-and-socket joint between the threaded stem and the base pad. That joint lets the pad tilt independently of the stem, so the full face of the pad stays in contact with the floor even when the leg it is fitted to is a few degrees off vertical.

That matters because frames are rarely perfectly square. A welded or bolted frame, a frame standing on a floor with a fall, or a frame whose legs have been cut slightly long on one side all load the foot at an angle. A rigid foot then bears on one edge, which concentrates the load and lets the frame rock. The ball joint removes that edge loading, which is why it is the default foot on adjustable machine frames.

What the ball joint does that a rigid foot cannot

Two things happen when a rigid levelling foot meets an angled leg. The pad tilts off the floor and contacts on one edge, and the stem bends. The edge contact raises the pressure under the pad by an order of magnitude and, on a smooth floor, lets the frame slide; the stem bending puts a permanent set into the thread over time, so the foot loses its adjustment range.

A ball foot absorbs the angle at the joint instead. The pad stays flat, the stem stays straight, and the load is spread over the whole pad face. The angle a ball foot will absorb is typically 10 to 15 degrees off vertical, which covers almost every real frame.

Stem	Pad diameter	Static load per foot	Typical frame
M8 × 40 mm	40 mm	400 kg	Light benches and instrument stands
M10 × 50 mm	50 mm	600 kg	Workbenches and light machine frames
M12 × 60 mm	60 mm	1,000 kg	Machine frames and assembly stations
M16 × 80 mm	80 mm	2,000 kg	Heavy machinery and gantry bases

Reading the load rating correctly

Static, not dynamicThe load figure is a static compression rating. A frame that is pushed, or that sees vibration from the machine on it, has to be derated — a dynamic installation is normally quoted at about half the static figure.

Per foot, not per frameA four-leg frame does not divide its weight by four. Uneven floors mean one leg usually carries little or nothing, so the safe design rule is that three feet share the total load.

Compression onlyA levelling foot is designed for compression. Where a frame is lifted by the feet, or where a foot sees a pull-out load, the stem needs a locking nut and the thread engagement has to be checked.

Choosing the base material

Nylon (PA6) base is the default. It does not mark epoxy, vinyl or painted floors, it damps vibration, and it is electrically insulating, which matters on equipment frames.
Steel base with a nylon insert is used where the pad has to resist a side load — a frame that is pushed across a floor — because the steel shell takes the shear rather than the polymer.
Stainless steel base is specified for wash-down and outdoor installations, and for food and pharma frames where a bare steel pad would corrode.

Practical point: send us the frame weight, the number of legs and the floor the frame stands on. We will return the stem size, the pad diameter and the per-foot rating including the three-foot derating, before you commit to a thread size.

Fitting the foot to the profile

Decide the fixing method A foot with a plain threaded stem screws into a tapped end or a thread insert in the profile. A foot with a base plate bolts to the end face instead. The profile end detail decides which.
Tap or insert the end Standard profile ends take an M8, M10, M12 or M16 thread insert pressed or hammered into the core hole. Off-the-shelf feet are supplied to the same thread standard, so no adaptor is needed.
Set the frame level Adjust the feet under load, not on an unloaded frame, because the frame settles as the weight comes on. Level the frame with the machine in place.
Lock the adjustment Fit the locking nut and tighten it against the profile end. Without it, vibration walks the foot out of adjustment within weeks.
Check the pad contact Slide a feeler gauge under the pad. On a ball foot the pad should be flat on the floor; if it is not, the joint is at the limit of its angle and the leg needs shortening rather than more adjustment.

Frequently asked questions

How much angle will a ball foot absorb?

Typically 10 to 15 degrees off vertical, which is more than almost any real frame needs. Beyond that the socket reaches its limit and the pad starts to edge-load again.

Can a ball foot be used on a frame that is moved?

It can, but the load rating has to be halved for a dynamic installation and the base should be steel rather than nylon, because a moving frame puts a side load through the pad.

Do I need a locking nut?

Yes, wherever the frame sees vibration. The nut locks the stem against the profile end so the setting cannot walk.

What thread sizes are available?

M8, M10, M12 and M16 are standard. Metric and UNC threads are both available, and a custom stem length is quoted from the drawing.

Will the nylon pad mark the floor?

No. PA6 nylon is the standard choice for epoxy, vinyl and painted floors because it does not mark or scuff them, and it also damps vibration.

Tell us the frame weight and the floor

Send the frame weight, the number of legs and the floor condition. We will return the stem size, pad diameter and per-foot rating including the three-foot derating, with FOB pricing within one working day.

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