Which wheel on which glass edger: a selection matrix

Straight-line, double, beveling and four-edge machines grind glass differently. A station-by-station matrix of the wheel each family takes.

The machine family comes first

Two wheels with the same diameter and grit are not interchangeable if they were built for different machine families. What changes is the rim form, the work layer and how the wheel is mounted. A double edger runs two heads against the two edges at the same time and loads both symmetrically; a beveling machine works at an angle and needs a different rim. Get the family right and the rest of the choice is arithmetic.

The matrix

Machine family	Station 1 — rough	Station 2 — medium	Fine grinding	Polishing
Straight-line edger	Continuous rim metal, 130–200 mm, #80–#180	Inner segmented metal, 150 mm	Resin bond, 130–175 mm, #180–#400	10S PU 150×70×40, or final polish 150×70×30/40
Double edger	Full segmented metal, 150 / 175 mm, #60	Inner segmented metal, 150 mm	Resin bond, 130–175 mm	10S PU, or final polish wheel
Beveling machine	Semi-segmented metal, 150 mm, layer 6×12 or 8×14	Resin bevel wheel, 150 mm, #170–#700	—	10S PU narrow edge, 130×60×10
Four-edge machine	Metal, 160 mm, 2 pcs per set	Resin, 160 mm, 2 pcs per set	—	—
Shape machine / CNC	Profile diamond wheel, 35–200 mm	BD silicon carbide, 100–200 mm	—	—

Straight-line edger

The most common machine in the shop, and the one where the stack is most often copied from a neighbour. Four to nine spindles, working one edge at a time. Station one carries the removal, so it takes a continuous rim metal wheel — the unbroken rim keeps the removal rate flat and holds geometry from the first piece to the last. The last station is a polyurethane wheel, high- or low-speed grade depending on spindle rpm, not a diamond wheel.

Double edger

Two edges at once, both heads loaded symmetrically, which is why the rough station here takes a full segmented rim and a coarser grit (#60) than a straight-line machine of the same size. Segments clear the swarf faster on the heavier removal. Fine and polish stations are the same family of wheels as the straight-line machine — only the mounting differs.

Beveling machine

Works at an angle on the edge, so the rim form matters more than the diameter. Semi-segmented metal at rough keeps the bevel angle while clearing glass, and a resin bevel wheel from #170 to #700 follows. Polishing on this machine is usually a narrow-edge PU wheel rather than a wide one, because the contact patch is a bevel, not a flat.

Four-edge machine

Two wheels per set, 160 mm, mounting holes drilled to the machine brand — this is the one family where the bore is not a standard size and the set has to be paired. Metal for the rough positions, resin for the fine positions, and the pair must be matched or one edge will read differently from the other.

Shape machine and CNC

Here the profile is the product: a profile diamond wheel from 35 to 200 mm OD with bore and profile to the drawing, followed by a BD silicon carbide wheel for the curve polish. Grinding and polishing happen on different wheels with different shapes, so the drawing is the only reliable starting point.

The four numbers that decide most of the choice

Glass thickness sets the work layer, not the diameter.
Removal per pass sets the grit at station one.
Spindle rpm decides high-speed or low-speed polishing compound.
Target edge decides whether the last station is PU or felt with cerium oxide.

What we need to quote correctly

Machine brand and model, or a photo of the spindle head.
Spindle count and which position the wheel sits in.
The wheel you run now: outer diameter, bore, work layer.
Glass thickness range and removal per pass.
The finish you need on the edge.

Send those and the answer is a specification, not a catalogue page.

Where this matrix stops

Custom profiles, glass under 2 mm, and machines with non-standard bores fall outside it. Send the drawing or the dimensions of the wheel you run now, and we work from that instead of from a table.