How to Use a Metal Lathe: Full Guide and Which to Choose

To use a metal lathe you clamp the workpiece in the chuck, set the speed according to diameter and material, and feed the tool against the rotating workpiece. An entry-level benchtop lathe such as the Bernardo Profi 300 V starts at €1,391. Krollit has been an official Bernardo distributor since 2007.

At Krollit we have been selling metal lathes for almost twenty years. The most common beginner's mistake is running the spindle too fast and ruining the cutting edge. This guide covers the parts of the machine, step-by-step use, the right speed, the tooling and which lathe to choose from our range.

The metal lathe rotates the workpiece while a fixed tool removes chips, producing cylindrical and conical surfaces, threads and centred holes. Knowing the five main parts makes every later step easier to follow.

The headstock houses the motor and drives the spindle, where the workpiece is clamped. The tailstock, at the opposite end, supports long workpieces and prevents deflection. The bed is the ground cast-iron base on which everything slides.

The carriage holds the tool and moves in two directions: longitudinally along the workpiece for length, and transversely to reduce the diameter. The toolpost locks the tool at centre height. The leadscrew drives the automatic feed and is used to cut threads at a constant pitch.

Using it follows seven steps, from clamping the workpiece to the final dimension. The first pass should always be light, to check concentricity before removing material.

1. Clamp the workpiece. Tighten the workpiece in the self-centring three-jaw chuck and turn it by hand to check that it does not wobble. For long workpieces, support the end with the tailstock.
2. Mount the tool. Fix the tool in the toolpost with the tip exactly at the centre height of the workpiece. A tip that is too high or too low leaves a pip in the centre and tears the chip.
3. Set the speed. Set the speed according to diameter and material, using the table below. Large diameters need few revolutions.
4. Approach and take the first pass. Bring the tool up with the machine running and take off half a millimetre to read the real concentricity of the workpiece.
5. Feed steadily. Use the manual or automatic feed at a constant speed, without jerks that leave steps on the surface.
6. Measure after every pass. Stop the machine and check the diameter with a caliper, approaching the target dimension in small steps.
7. Finishing. Reduce the feed and take a light final pass, with cutting fluid, for a clean surface.

The speed is calculated from the material's cutting speed using the formula rpm = (Vc × 1000) ÷ (π × diameter in mm). The larger the diameter, the fewer revolutions are needed. With carbide tooling the speeds double or triple compared with high-speed steel.

Sandra Gaspar's advice
If you are just starting out, always begin at the low speeds in the table. A tool that smokes or a chip turning blue means you are going too fast: slow down and use cutting fluid. Burning an edge costs more than the time you think you are saving.

Lathe tools are made of high-speed steel (HSS), cobalt HSS (HSS-Co) or carbide with indexable inserts. The choice changes working speed, edge life and tolerance for error.

HSS can be reground by hand on the grinder and forgives knocks, so it is the starting choice for beginners. Cobalt HSS copes better with heat on stainless. Carbide cuts faster and lasts longer, but chips if it hits an edge or an inclusion.

To get started, a set of lathe tools and chucks in 12 mm HSS with 9 pieces starts at €224. Interchangeable carbide inserts (9-piece set from €261) pay off when you work in batches and do not want to stop to regrind.

Our Bernardo range runs from the small benchtop lathe for hobby work and spare parts up to industrial and CNC lathes for production. The right class depends on the maximum diameter, the length of the workpieces and the operating hours.

For anyone short of space, the Bernardo Proficenter 550 WQV combines lathe and mill in a single machine (from €3,599), with a 2-axis digital readout.

For hobby work and spare parts a benchtop lathe such as the Profi 300 V (€1,391, single-phase 230 V) turns steel up to modest diameters. For continuous work, stainless steel or workpieces over a metre, move up to the Profi 550 or 700, stiffer and with automatic feed.

For precision what counts is the rigidity of the bed and the play in the slides, not just the price. An entry-level lathe holds tolerances around ±0.05 mm; for tighter dimensions you need models with a digital readout and adjustable slides, up to the CNC lathes for batch production.

Building a lathe at home is a long project and rarely a precise one, because a home-built bed flexes and loses concentricity. A benchtop model or a reconditioned used machine starts out within tolerance and costs less than the material and the mistakes.