Taper Lock Bush Size Chart 1008 to 4040
Taper bushes run from size 1008, 22.3 mm long and 35 mm across the large end, to 5050; each is a split, tapered sleeve that pulls itself into a matching hub when its screws are tightened and grips the shaft like a shrink fit. The table covers 1008 to 4040, where most sprockets, pulleys and couplings sit. EKINSUN LTD is a custom parts manufacturer that machines the hubs, sprockets and pulleys these bushes go into and bores bushes to sizes no list carries.
| Size | Length (mm) | Large-end Ø (mm) | Screws (qty × BSW) | Hex key (mm) | Screw torque (Nm) | Largest bore from the size number (in) | Largest metric bore, standard keyway (mm) |
|---|---|---|---|---|---|---|---|
| 1008 | 22.3 | 35 | 2 × 1/4 | 3 | 5.6 | 1 | 25 |
| 1108 | 22.3 | 38 | 2 × 1/4 | 3 | 5.6 | 1.1 | 28 |
| 1210 | 25.4 | 47.5 | 2 × 3/8 | 5 | 20 | 1.2 | 32 |
| 1610 | 25.4 | 57 | 2 × 3/8 | 5 | 20 | 1.6 | 42 |
| 1615 | 38.1 | 57 | 2 × 3/8 | 5 | 20 | 1.6 | 42 |
| 2012 | 31.8 | 70 | 2 × 7/16 | 6 | 30 | 2 | 50 |
| 2517 | 44.5 | 85.5 | 2 × 1/2 | 6 | 50 | 2.5 | 60 |
| 3020 | 50.8 | 108 | 2 × 5/8 | 8 | 90 | 3 | 75 |
| 3030 | 76.2 | 108 | 2 × 5/8 | 8 | 90 | 3 | 75 |
| 3525 | 63.5 | 127 | 3 × 1/2 | 10 | 115 | 3.5 | per maker |
| 3535 | 89 | 127 | 3 × 1/2 | 10 | 115 | 3.5 | per maker |
| 4030 | 76.2 | 146 | 3 × 5/8 | 12 | 170 | 4 | per maker |
| 4040 | 102 | 146 | 3 × 5/8 | 12 | 170 | 4 | per maker |
A hub, sprocket or pulley for one of these bushes? Name the bush size, the shaft and keyway, the part and the quantity. Standard bushes can also be supplied from stock; taper-bored parts are made from 1 piece, and the more pieces, the lower the unit price. Quote in 12 hours.
Lengths, large-end diameters, screws, hex keys and torques from one bush maker’s engineering data, lengths and screw sizes checked against a second maker’s dimension table; the largest metric bore is the largest standard bore with a full keyway, and larger bores with shallow keyways exist for some sizes. Torque figures are that maker’s; use the figure printed with the bush you fit.
Reading the Size Number: 1610, 2012, 2517
The first two digits are the largest bore in tenths of an inch, the last two the length in tenths of an inch, rounded (a 1008 is 0.875 in, 22.3 mm): 1610 is up to 1.6 in bore and 1.0 in long, 2012 up to 2.0 in and 1.25 in long, 3030 up to 3.0 in and 3.0 in long. Sizes with the same first two digits, such as 1610 and 1615 or 3020 and 3030, share a large-end diameter and screws and differ only in length.
How Big the Hub Must Be
A 1610 bush needs a hub of at least 85 mm outside diameter in steel of 420 N/mm² and 92 mm in cast iron of 250 N/mm², by one maker’s figures; a 3020 needs 140 and 146 mm. The bush wedges into its hub like a shrink fit, and the hub has to contain that stress. A hub, a weld-on hub or a sprocket body smaller than this is the wrong size for the bush, however well it is bored.
| Size | Cast iron 250 N/mm² | Steel 420 N/mm² |
|---|---|---|
| 1008 | 54 | 51 |
| 1108 | 57 | 54 |
| 1210 | 86 | 78 |
| 1610 | 92 | 85 |
| 1615 | 81 | 77 |
| 2012 | 106 | 99 |
| 2517 | 119 | 113 |
| 3020 | 146 | 140 |
| 3030 | 136 | 132 |
| 3525 | 191 | 178 |
| 3535 | 176 | 168 |
| 4030 | 207 | 197 |
| 4040 | 195 | 188 |
Which Bush Fits a Sprocket: Pitch Circle, Root Diameter and Hub
The pitch circle of a sprocket is the pitch divided by sin(180° / teeth); the root diameter is the pitch circle less the roller diameter. An 08B sprocket with 25 teeth has a 101.3 mm pitch circle and a root diameter of about 92.8 mm, which leaves room for a 1610 bush in a steel hub. With 15 teeth the root diameter is 52.6 mm and only a sprocket with a raised hub takes a bush.
| Chain | Pitch (mm) | 15 teeth | 19 teeth | 25 teeth |
|---|---|---|---|---|
| 06B | 9.525 | 45.8 / 39.5 → – | 57.9 / 51.5 → – | 76 / 69.6 → 1108 |
| 08B | 12.7 | 61.1 / 52.6 → – | 77.2 / 68.6 → 1108 | 101.3 / 92.8 → 1610 / 1615 |
| 10B | 15.875 | 76.4 / 66.2 → 1108 | 96.4 / 86.3 → 1615 | 126.7 / 116.5 → 2517 |
| 12B | 19.05 | 91.6 / 79.6 → 1615 | 115.7 / 103.7 → 2012 | 152 / 139.9 → 3030 |
| 16B | 25.4 | 122.2 / 106.3 → 2012 | 154.3 / 138.4 → 3030 | 202.7 / 186.8 → 3525 / 3535 |
A sprocket with a tooth count or hub the catalogue lacks? tap its row, or send the chain, tooth count and bush. Steel or stainless; single or double; from 1 piece.
Pitch and roller diameter per ISO 606 / DIN 8187 B series. The last value in each cell is the largest bush whose steel-hub minimum is at least 2 mm under the root diameter; a raised hub on the side of the sprocket takes a larger bush.
Taper Bush, Pilot Bore or Keyless Locking Device
A sprocket, pulley or coupling reaches the shaft in one of three ways: a taper bush from 1008 to 4040, a pilot bore that is bored and keyed to one shaft, or a keyless locking device. The taper bush wins wherever parts are changed in service, because the hub stays and only the bush changes with the shaft.
| Taper bush | Pilot bore, bored and keyed | Keyless locking device | |
|---|---|---|---|
| Fitting | Screws pull the bush into the hub; no machining on site | Bored and keyed to the shaft, held by a set screw | Screws expand rings between shaft and hub |
| Shaft change | Change the bush, keep the hub | Re-bore the part, or a new part | Change the device if the size range allows |
| Removal | Screws moved to the removal holes push the bush out | Puller | Release the screws |
| Choose it when | Sprockets, pulleys and couplings changed in service | One shaft size for the life of the part | No keyway allowed, high torque, exact angular position |
Standard Bushes From Stock, Taper-Bored Parts Made to Order
Standard bushes from 1008 to 4040 with listed bores are on every power-transmission distributor’s shelf. Odd bores, taper-bored hubs and sprockets outside the catalogue are where we start.
| What you need | On the shelf? | What we do |
|---|---|---|
| A standard taper bush with a listed metric or inch bore | Yes — every power-transmission distributor | Buy it there, or ask us: standard bushes can also be supplied from stock. |
| A bush bored to an odd size, an inch bore in a metric bush, or a shallow keyway | Rarely | Bored and keyed to your shaft within the body’s range, from 1 piece. |
| A weld-on or bolt-on hub, or your part taper-bored for a bush | Weld-on hubs in common sizes only | Hub or part machined with the taper bore and tapped half-holes, sized to the minimum hub table. |
| A sprocket with a tooth count, pitch or hub the catalogue does not list | No | Teeth cut to ISO 606 for the chain, taper-bored, single or double, steel or stainless. |
| A stainless bush and hub for food or wash-down lines | Seldom | Bush and hub in 304 (1.4301) or 316L (1.4404) stainless, hubs otherwise in C45 steel, sized to the same table. |
| A coupling or drive certified as an assembly | — | We machine the parts to your drawing; the drive rating stays with its designer. |
Shafts and keyways for these parts are on custom keyed shafts and the keyway size chart; worn drive parts on conveyor replacement parts; the pillow blocks the same shafts run in, with UCP 204 to 212 sizes, on bearing housing replacement. For distributors we pack neutrally, print your part number on the label and ship to your customer.
What to Send for a Taper-Bored Part
Five details price a taper-bored part: the bush size (1008 to 4040), the shaft diameter and keyway; the part — hub (weld-on, bolt-on or your drawing), sprocket (chain, tooth count, single or double) or pulley (belt section and grooves); the material and the quantity. A photo of the old part with a rule beside it is enough to start. The quote comes within 12 hours, and a dimensioned drawing of the hub or sprocket comes back for your approval before any cutting.
Taper Lock Bushes and Hubs — Buyer Questions
The first two digits are the largest bore in tenths of an inch and the last two the length in tenths of an inch. A 1610 bush takes bores up to about 1.6 in (listed as 42 mm) and is 1.0 in (25.4 mm) long; a 2517 takes up to about 2.5 in and is 1.75 in (44.5 mm) long. Bushes of the same first two digits, such as 1610 and 1615, fit the same hub bore family but differ in length.
One bush maker gives 5.6 Nm for 1008 and 1108, 20 Nm for 1210, 1610 and 1615, 30 Nm for 2012, 50 Nm for 2517, 90 Nm for 3020 and 3030, 115 Nm for 3525 and 3535 and 170 Nm for 4030 and 4040. Tighten the screws alternately, tap the large end of the bush, tighten again, and recheck after a short run under load.
At least 85 mm outside diameter in steel of 420 N/mm² and 92 mm in cast iron of 250 N/mm², according to one maker's engineering data; the bush wedges like a shrink fit and the hub must contain that stress. A 2012 needs 99 mm in that steel, a 2517 113 mm and a 3020 140 mm.
Yes. Bushes are made in metric and inch bores with matching keyways, and a bush can be bored to an odd size within the range of its body, such as a 1610 to 1-3/8 in or 35 mm with a shallow keyway. We bore bushes and machine the hubs, sprockets and pulleys that take them, from 1 piece.
An 08B (1/2 in) sprocket with 25 teeth has a pitch circle of 101.3 mm and a root diameter of about 92.8 mm, so a hub up to roughly 90 mm fits inside the teeth; that is enough for a 1610 bush in a steel hub, which needs 85 mm. Fewer teeth leave a smaller hub and a smaller bush, or a hub that stands out of the plate.
EKINSUN — a custom parts manufacturer in Shenzhen that taper-bores hubs, weld-on and bolt-on hubs, sprockets and pulleys for bushes from 1008 to 4040, bores bushes to odd metric and inch sizes and makes sprockets with tooth counts no catalogue lists, in steel or stainless, from 1 piece; neutral packaging and delivery to the end customer for distributors. Quote in 12 hours.