Locomotive wheel defect limits in Canada and the United States

4 October 2026

A locomotive wheel must come out of service when its flange is 7/8 inch (22.2 mm) thick or less. That limit is the same in Canada and the United States. The other limits are set out below.

Canada

The Railway Locomotive Inspection and Safety Rules apply to railway companies under Transport Canada jurisdiction. Part III lists wheel conditions that are not permitted, including:

Railways that operate only inside one province answer to a provincial regulator, such as Technical Safety BC in British Columbia. Check with yours which version of the rules applies to your operation.

United States

Title 49 of the Code of Federal Regulations, section 229.75, lists wheel and tire defects for locomotives. A flange worn to 7/8 inch or less, measured at a point 3/8 inch above the tread, is condemned. The same section covers flat spots, tread wear, cracks and other defects. Read the section itself for the full list before writing a shop standard.

What this means for planning

• Measure before the limit, not at it. A wheel at 15/16 inch flange thickness is legal today and a failed inspection soon. Order when you see the trend.
• Wheelsets have long lead times. Wheels, axles and gears are safety-critical parts with few sources.
• Ask for the paperwork. A certificate of conformance and the shop's quality certification should come with the wheelset.

When you ask for a quote on a wheelset, give the unit model, wheel diameter, gear ratio and whether you can return the old set as a core. You can add a wheelset to an RFQ here.

This article is a summary for planning. The rule text governs.

Sources

• Railway Locomotive Inspection and Safety Rules, Part III, Transport Canada
• 49 CFR 229.75, Wheels and tire defects, eCFR
• Railways, Technical Safety BC