A linear slide is defined by its bearing: rolling elements running on hardened rails, driven by a screw, belt or rack. A cross slide is defined by its arrangement: two orthogonal axes stacked so the table can move in X and Y. You can build a cross slide from linear rails, from dovetail ways, or from a mix. That is why the comparison confuses people — the two words describe different axes of the same question.
Clearing up the definitions
In our catalogue, a linear slide table means a single-axis assembly with profile rails, a preloaded carriage and a ball screw — the LX160 is the reference example. A sliding worktable means a dovetail-way table with a T-slot top, supplied as a single axis or as an XY cross slide — the dovetail cross slide.
So the real question is not "linear or cross" but "rolling or sliding ways, and one axis or two". Both axes can be either type.
| Property | Profile rail (rolling) | Dovetail (sliding) |
|---|---|---|
| Typical accuracy | ±0.01 mm | ±0.02 mm |
| Repeatability | ±0.005 mm | ±0.01 mm |
| Friction | 0.002–0.003 µ | 0.05–0.1 µ, stick-slip at low speed |
| Stiffness per mm of height | Moderate | High |
| Stack height, single axis | rail + carriage + table | rail + swivel + table |
| Speed | Up to 1500 mm/s | 100 mm/s motorised, manual otherwise |
| Contamination tolerance | Poor without wipers | Good, scrapes contamination aside |
| Cost at same travel | Higher | Lower |
Stack height decides more designs than accuracy does
A dovetail cross slide adds 132 mm; a rail-based XY stack adds 190–220 mm because each axis needs its own carriage and base plate. On a bench drill, an EDM head or a small optical instrument, that 60–90 mm often exceeds the available Z travel, and the design dies there. This is the single most common reason a dovetail table wins a project that "needed" a linear stage.
Stiffness and damping
A scraped dovetail is stiff in compression and very stiff in the direction perpendicular to the ways, because the contact area is large. A profile rail is stiff too, but its stiffness is concentrated at four contact points, and the carriage can rock if the load is offset. Under a drilling thrust, a locked dovetail is effectively rigid; a rail slide depends on preload and block count.
Damping is the other half. Cast iron and a scraped surface absorb vibration; a rail contact does not. On a light finishing cut the rail slide wins on accuracy. On an interrupted cut with a large tool, a dovetail machine often produces a better surface for the same tolerance.
Speed and stick-slip
Dovetail ways have high static friction and low kinematic friction, which produces stick-slip at very low feed rates — the table moves in jumps of a few microns instead of smoothly. For manual positioning this is invisible. For a CNC contour at 5 mm/min it is a defect. Rolling ways have almost no friction difference between static and moving, which is why they are used for any continuously interpolated axis.
Which one for which job
- Drilling, tapping, EDM, light milling fixtures — dovetail cross slide. Lock it and it will not move. Low stack height, low cost.
- CNC contouring, grinding, precision boring — profile rail slide table. No stick-slip, higher speed, tighter repeatability.
- Transfer and pick-and-place — belt module. Neither of the above; the constraint is cycle time.
- Retrofit where the original was a dovetail — match the original way type unless you are prepared to change the control and the fixturing as well.
Selection shortcut
Answer two questions and the choice is usually settled.
- Does the axis interpolate while cutting?
- Yes → profile rail
- Is Z travel within 100 mm of the limit?
- Yes → dovetail
- Is the load offset from the carriage centre?
- Yes → dovetail or twin carriage
- Is speed above 200 mm/s?
- Yes → profile rail or belt
The hybrid that often wins
A common compromise is a dovetail slide for the axis that carries the cutting thrust and a rail slide for the axis that only positions. On a drilling machine that means a dovetail XY table under the work and a rail slide on the head. It costs less than two rail axes and produces a stiffer machine than two dovetails.
If you are unsure, describe the cut and the load offset and we will tell you which way type we would build — including the cases where the cheaper option is the correct one. Both families are built in the same factory, so the recommendation is not driven by what we would rather sell.
Common questions
Yes. It is a stacked XY assembly on profile rails, taller and more expensive than a dovetail but with better repeatability and no stick-slip.