MCGILL MI 25 4S needle roller bearing

McGILL MI 25 4S belongs to needle roller bearing, part of our Bearings range. Tell us how many you need by WhatsApp or email and we'll get back to you promptly with a quote for MI 25 4S and any equivalents.

When a housing leaves almost no radial room but the shaft still has to carry a radial load, the MCGILL MI series needle roller bearing is often the answer. Its very small radial section lets it sit where a ball or roller bearing would not physically fit, which is why it shows up in machine tools, transmission equipment and mechanisms that call for accurate rotation inside a small outside diameter. MR Industrial Accessories supplies this line and can help you pin down the exact size from the code stamped on the part.

Reading the code is the fastest way to identify what you have. The MI letters mark the needle roller bearing family; the first figure refers to the shaft or bore diameter, depending on the case; the closing figure sets the width or the sealing variant. Where an S appears, it points to a version with a seal or lateral protection. For a quote, copy the full code exactly as it is marked on the component or shown on the drawing.

Radial space is the deciding factor in most of these applications: machine tools, presses, packaging lines, chain and belt drives, and lifting mechanisms. The same bearing turns up in pumps, compressors and textile equipment. Because it handles radial loads with such a low profile, it is also common in gearboxes and in joints that oscillate rather than rotate continuously at high speed.

Selection comes down to three things: shaft diameter and its tolerance, the width you have available, and the nature of the load. The MI series can run directly on a shaft that is ground and hard enough, or on a separate inner raceway. The S seal keeps out dust and moisture, but it needs a lubricant that suits it. Shaft-to-housing alignment matters as well, since too much misalignment cuts the working life of the needles.

On interchangeability, needle roller bearings follow standardized dimensions, yet every manufacturer applies its own nomenclature. You cannot swap an MCGILL MI code for another brand's number without first checking diameter, width and seal type. If you need an alternative, send the measured dimensions or the original code and the interchangeability will be reviewed.

MR Industrial Accessories carries MCGILL as part of its bearing range. If an MI series needle roller bearing is what you need, message us on WhatsApp with the code, or with the shaft and housing dimensions, and we will come back with the option that fits your equipment.