Bison Tooling

Bison (properly Bison-Bial) is a Polish manufacturer with a long-established reputation for producing high-precision workholding and toolholding to a consistently high standard.

The range featured in our category here is manufactured entirely within Bison’s own factory in Poland, which is the foundation of the quality the brand is known for.

In a market flooded with budget copies, Bison stands apart because the quality is built in rather than inspected in.

The scroll chucks, independent chucks, vices, centres & toolposts are machined to close tolerances from good materials and they hold their accuracy over a long working life.

That is why the name carries weight with time-served engineers: a Bison chuck is a purchase you expect to still be running true decades after you bought it.

It is a comprehensive workholding and toolholding catalogue.

On the workholding side you will find lathe chucks; 2, 3, 4 & 6-jaw, scroll and independent, machine vices including 5-axis vices, power chucks, lathe centres (both dead and revolving live centres), tailstocks and a full selection of jaws and workholding accessories.

On the toolholding side there is the Bison quick change toolpost system and its holders, covered in detail in its own FAQ section.

Taken together, the range lets you equip a lathe or mill almost entirely from one reputable supplier, which keeps the quality consistent across the workshop and simplifies spares and accessories.

A scroll chuck (the familiar 3-jaw self-centring type) has all its jaws driven in together by a single internal scroll plate, so they close on the work simultaneously and centre it automatically. It is fast to load and the go-to for round and hexagonal bar, which is why it ships on most lathes as standard.

An independent chuck has each jaw adjusted on its own screw, so they are set individually. That makes it slower to set up, but it will grip square, rectangular and irregular work that a scroll chuck cannot and it allows you to dial a part in to run true to a few thou which is essential for precision and eccentric work.

Bison makes both, in cast iron and steel bodies so the choice is driven by the work, not by what is available.

The number of jaws is chosen to suit the shape and sensitivity of the work. A 2-jaw chuck grips awkward, asymmetric and rectangular components that need firm location on two opposing faces, and it is widely used for gripping castings and forgings where a profiled soft jaw cradles the part.

A 4-jaw independent chuck is the precision workhorse because it holds square and irregular stock and lets you dial the part concentric to an existing feature.

A 6-jaw chuck spreads the clamping force across more contact points, which is ideal for thin-walled tubes and rings that would distort under the localised grip of a 3-jaw.

For most general turning the 3-jaw covers the work; the others earn their place when the workpiece shape demands them.

Bison offers both, and the choice is driven by how the chuck is used. A cast iron body damps vibration well and is the traditional choice for heavy turning and interrupted cuts because it absorbs shock, holds its accuracy over a long life and is gentle on spindle bearings when chucks are swapped regularly.

A steel body is tougher and more resistant to impact, which suits high-speed running and environments where chucks are handled and changed frequently. Steel bodies are often found on chucks intended for higher spindle speeds, where balance and resistance to distortion at speed matter.

Both materials are made to Bison’s standard; pick cast iron for heavy general turning, steel where speed and durability under handling are the priority.

The mount is how the chuck bolts to your lathe spindle and it must match the spindle nose exactly (there is no useful workaround for a mismatch).

Bison offers plain back mounting to DIN 6350, where a separate backplate is machined to suit your spindle register;

• Type A (DIN 55026)

• Type C bayonet (DIN 55027)

• Type D camlock (DIN 55029)

Camlock Type D is the most common on modern lathes (the chuck locates on the spindle register and locks with cam studs). Bayonet Type C twists and locks, while Type A uses a short taper with bolts.

Plain back is the most universal, because the backplate is machined in place to give a true-running fit.

Check your lathe’s spindle specification before ordering and if you are unsure, our in-house engineers can help identify the mount from your machine details.

Chuck diameter is matched to the swing and the work you do. The range runs from 80mm (3") up to 630mm (25"), covering everything from small bench lathes to large industrial turning machines.

As a rule, choose the largest chuck the swing comfortably allows for general work, because a larger chuck gives more grip and better support, but do not oversize it to the point where the chuck overhangs the spindle nose or unbalances the machine.

The mount must match your spindle nose and the through-bore must clear the bar you intend to feed.

If you are replacing an existing chuck, the simplest path is to match the diameter and mount of the one coming off. Our in-house engineers can help confirm the correct size and mount from your lathe model.

Lathe centres support the free end of a workpiece held between centres or in a chuck, giving rigidity to long or slender parts. A dead centre is a plain hardened point that sits static in the workpiece centre hole (simple and accurate), but the work spins on it, so it needs lubrication and is suited only to low speeds.

A revolving live centre has its own bearings, so the point rotates with the work. That eliminates the friction and heat of a dead centre, allowing higher spindle speeds and heavier cuts without burning the centre hole.

For anything beyond low-speed manual work, a live centre is the practical choice. Bison offers both, in Morse taper shanks sized to the machine, with heavy-duty live centres for large or long work.

A power chuck is actuated pneumatically or hydraulically rather than by a manual key. The jaws open and close under powered actuation, giving consistent, repeatable clamping force and very fast loading and this is why they are the standard on production lathes and CNC turning centres running batch work.

For a manual or low-volume machine a standard scroll chuck is usually the better fit. A power chuck earns its place where cycle time and consistent clamp force matter, for example in production turning, where powered actuation removes the manual loading time and gives repeatable grip part after part. They require a suitable actuator on the machine, so they are a choice for machines set up for powered clamping.

A 5-axis vice is designed to hold a workpiece on a machining centre in a way that exposes five faces of the part to the cutter in a single set-up. The clamping is deliberately low-profile and out of the way, so the spindle can reach around the part without the vice body obstructing the tool path.

That single-set-up access to multiple faces is what makes 5-axis vices valuable on modern machining centres because it cuts set-up time, improves accuracy by avoiding re-clamping and lets you finish a complex part in one hit. A standard machine vice by contrast, is built for rigid grip on simpler milling jobs. Bison offers both, so the choice follows the machine and the work.

The Bison machine vices are precision-ground, single-body vices built for repeatable, rigid clamping on a milling machine. Match the jaw width and opening to the largest part you realistically hold and the overall length to the machine table (a vice that is too large steals travel and may not seat properly in the T-slots).

A precision Bison vice repeats better and holds tighter than a budget equivalent and the difference shows up immediately in finish and accuracy on finished parts. The clamping force, the quality of the guideways and the ability to accept both solid and soft jaws are what set a good vice apart and Bison vices score well on all three.

Bison workholding is manufactured to close tolerances and the accuracy figures are stated on the product, for example, the revolving live centres we stock carry a stated runout of 0.003mm. In practice, that means a new Bison chuck will run true to a few microns when correctly mounted and hold that accuracy over a long working life provided it is cared for.

It is worth noting that the accuracy of a chuck is only as good as its mounting. A perfectly made chuck on a worn or poorly-machined backplate will run out. So fit the chuck correctly to a true spindle register, verify runout with a dial indicator after fitting and the Bison accuracy will be what you see at the workpiece.