Machine feet SF38

Not every machine foot needs a spindle of its own. Machine foot SF38 is a damped foot in zinc plated steel with a threaded hole; you choose the spindle yourself in the form of a stud, a machine screw or the existing threaded spigot on the frame. That makes the foot a flexible building block for the designer who wants to decide the length, grade and material of the screw instead of getting it as part of the package. The design is simple: a steel body, a threaded hole and a rubber damper, nothing that binds or loses its setting.

The series covers six sizes. The diameter runs from 80 to 200 mm and the threaded hole from M10 to M20. The smallest foot is rated for 300 kg of axial load, then follow 400, 500, 600 and 1 000 kg, and the largest foot with a diameter of 200 mm carries a full 3 000 kg. Note that thread size and load class do not follow each other directly; there is for example both an M12 foot for 400 kg and an M12 foot for 600 kg, so choose by both parameters. All dimensions per version are in the manufacturer's data sheet.

At the bottom sits a rubber damper that separates the machine from the floor. It takes up vibration and structure borne noise, protects the floor covering against pressure marks and gives the foot a grip that lets lighter equipment stand still without anchoring. A machine standing straight on steel or concrete sends every imbalance on out into the building structure; with rubber in the way a large part of the energy stays where it belongs.

The damper also makes assembly forgiving. Small angular errors between frame and floor are pressed out in the rubber instead of turning into play under one of the feet, which is what otherwise gives the classic rocking machine that never quite stands still.

The threaded hole opens up several ways of mounting. The most common is a stud screwed into both the frame and the foot, with a lock nut to hold the height once it is set. As an alternative a machine screw is pulled through the base plate of the frame straight down into the foot, a mounting that suits equipment that rarely needs readjustment. Keep the threads clean during assembly and do not tighten harder than lets the rubber sit flat; the foot is there to carry, not to be pulled up crooked.

Count on a margin when you spread the weight of the machine. Four feet rarely share it equally; the center of gravity sits at the motor and the gearbox, and small unevenness in the floor can leave one foot almost unloaded. It is better to pick one class larger than to sit at the limit, especially under equipment that gives shock loads. The load values apply to axial pressure; side forces have to be handled by the rest of the installation.

SF38 sits under compressors, pumps, fans, work benches, electrical cabinets and production equipment in dry indoor conditions, where the zinc plated surface stays good looking for many years. The largest sizes are used under heavier units where a wide bearing surface spreads the pressure against the floor. Feet with a threaded hole are also practical from a stock point of view; one and the same foot suits several different machines as long as the thread size matches, which keeps the number of items in the store down. If you need stainless for wet areas or food production, that is available among our other machine feet.

The feet are supplied by the pack with 25 or 50 per pack depending on size, a level that suits both machine builders in series and maintenance stores.

Would you like help choosing between the sizes, or do you need a data sheet? Get in touch with us.