
The Split Taper bushing is the higher-torque of the two Browning bushing systems. Its barrel is split twice so it closes evenly on the shaft rather than pulling to one side, its flange is solid so the bores stay concentric, and most sizes carry an external key that engages the hub. That external key is the point of the design: with the bushing keyed to both the shaft and the hub, the drive torque runs through steel and the cap screws only hold the taper closed. The taper itself is 3/4 inch per foot, which is self-locking, so the assembly stays put once tightened and comes apart again through the withdrawal holes.
Also known as: split taper bushing, browning bushings, h bushing, q1 bushing
Series in this category
Related guides: Split taper bushing sizes, Q-D bushing sizes, V-belt sheave sizes, Cross-reference help
| Specification | What it means |
|---|---|
| Bushing type | The letter, from G and H through P1, P2, P3, B, Q1, Q2, Q3, R1, R2, S1, S2 and the U, W and Y sizes. |
| Bore size and compatible bore | The finished bore the bushing is machined to, in inches or millimeters, within the span the letter covers. |
| Keyseat | The key cut in the bore, stated as width by depth. A few small bores are listed with no keyway. |
| Flange type | Solid flange or split-through flange. The solid flange is what keeps the bores concentric as the barrel closes. |
| Cap screws | How many screws draw the bushing into the hub and their thread and length, typically two, three or four. |
| Wrench torque | The tightening torque for those screws in inch-pounds, from about 95 on the smallest letters upward. |
| Length through bore and outside diameter | How far the bushing engages the shaft and how large it is overall, which is what the hub has to accommodate. |
It states how quickly the barrel narrows along its length: three quarters of an inch of diameter for every foot of length. That angle is shallow enough to be self-locking, so once the cap screws have drawn the bushing into the hub the assembly holds itself on the shaft and does not need a separate locking device. The same angle is used on every Browning Split Taper size.
The one its hub is bored for, and the sheave listing names it. Part numbers often carry it too: a trailing H on an AK or BK fractional sheave means an H bushing, and a trailing letter on a larger sheave number, as in 8C70Q, means a Q bushing. The shaft size then chooses the bore within that letter's range.
Yes, provided both hubs are bored for the same letter. The Split Taper system is common across Browning sheaves, sprockets and pulleys, which is part of why it is stocked so deeply: a plant that standardizes on a few letters can hold one set of bushings for several kinds of drive component.
So that the drive torque is carried by keys rather than by friction on the cap screws. The internal keyseat locks the bushing to the shaft and the external key locks it to the hub, which is what gives this system the highest torque capacity in the Browning bushing range. A small number of sizes are supplied without the external key, and those listings state it.