Motorcycle Whitworth Tools

WHITWORTH TOOLS FOR TRIUMPH, BSA, AND NORTON MOTORCYCLES

Standard SAE and metric tools do not fit Whitworth fasteners correctly. The thread angle on BSW (British Standard Whitworth) hardware is 55 degrees, compared to 60 degrees on standard and metric threads. The result of using the wrong tools is predictable: rounded bolt heads and fasteners that are nearly impossible to remove without extraction. If you are working on a vintage Triumph, BSA, or Norton motorcycle, a dedicated Whitworth wrench set and socket set is not optional, it is the starting point for any service or build work.

WHAT WHITWORTH THREAD HARDWARE IS ON YOUR BIKE

Knowing which fasteners on your British motorcycle are Whitworth matters before you start a job:

• Pre-1968 Triumphs: Early unit and pre-unit Triumph twins used Whitworth thread hardware across most of the bike, including engine, frame, and chassis fasteners. If the bike was built before 1968, assume Whitworth unless you have confirmed otherwise on a specific fastener.

• 1968 and Later Triumphs: From 1968 onward, Triumph began transitioning to a mix of Whitworth and standard UNC/UNF hardware across the engine and chassis. This means a 1970 Triumph may have both Whitworth and SAE fasteners on the same bike depending on the system. Having both tool sets accessible is the only reliable approach.

• BSA and Norton: BSA and Norton motorcycles of the same era used Whitworth hardware throughout. The same wrench set that covers a Triumph will cover BSA and Norton applications with the same size range.

• CEI Thread: CEI (Cycle Engineers' Institute) is a separate British thread standard used on wheels, wheel spindles, and some engine components across British motorcycles. CEI uses a finer thread pitch than BSW at equivalent diameters. The CEI tap and die set covers threading and rethreading work on CEI-spec fasteners where Whitworth taps and dies will not apply.

WHITWORTH TOOLS IN THE COLLECTION

All sets are from British Standard, with wrench sets by Rolson and socket sets by Koken:

• 8 pc Combination Wrench Set by Rolson: Drop-forged combination wrenches covering 1/8, 3/16, 1/4, 5/16, 3/8, 7/16, 1/2, and 9/16 inch Whitworth sizes. The starting point for any Triumph, BSA, or Norton build. The combination profile gives you both an open end and a box end on every size.

• 8 pc 12-pt Socket Set by Koken (3/8 inch drive): Twelve-point sockets in the same 1/8 through 9/16 inch WW size range on a 3/8 inch drive. Koken sockets are made in Japan and are the correct choice for fasteners in tighter access locations where a combination wrench cannot get the angle needed.

• 8 pc 6-pt Socket Set (1/2 inch drive): Six-point sockets on a 1/2 inch drive for higher-torque applications where the 3/8 inch drive is not sufficient. Six-point geometry is less likely to slip on a worn or corroded fastener head than a twelve-point socket.

• 8 pc 12-pt Deep Well Socket Set by Koken (3/8 inch drive): The deep well version of the Koken 12-pt set for applications where a standard-depth socket cannot reach the fastener. Stud-mounted components and recessed fasteners on British motors are where the deep well set earns its place.

• 6 pc 12-pt Socket Set by Koken (3/8 inch drive): A smaller socket set covering the most common Whitworth sizes for builders who need a compact set for road use or a secondary kit.

• CEI Tap and Die Set: Covers CEI thread sizes for rethreading damaged fastener holes and chasing threads on wheel spindles and related components. A necessary addition for any full restoration or teardown where thread damage is found on CEI-spec hardware.

For the full range of Triumph and BSA service tools beyond Whitworth, browse motorcycle engine tools and the complete vintage Triumph parts catalog.