What the 40 N.m continuous rating means for your load
The GBX0600050851G is a straight-tooth planetary gearbox from Schneider's GBX series, sized for applications where you need 40 N.m continuous torque at 100 rpm and can tolerate up to 64 N.m peak. That 40 N.m figure is the thermal limit at 30 °C — push it to 64 N.m and you're into the intermittent zone, likely shortening the 30,000-hour service life. With a 5:1 reduction ratio and 96% efficiency, the gearbox wastes only about 4% of input power as heat. For a small-shop owner paying the electric bill, that efficiency matters — it keeps the motor from working harder than it needs to.
Backlash, rigidity, and mounting — the fit constraints
Maximum torsional backlash is 16 arc.min, which is typical for a commercial planetary gearbox with straight teeth — not a precision servo reducer, but fine for positioning conveyors, indexing tables, or simple pick-and-place axes where a couple degrees of lost motion at the output won't crash the tooling. Torsional rigidity is 2.3 N.m/arcmin, meaning the shaft twists about 0.43 arcmin per N.m of applied torque. The housing is black anodized aluminium, the shaft is C45 steel, and the unit can be mounted in any position. The 60 mm external diameter fits standard clamp-style mounting brackets. Shaft output sealing is IP54 — splash-proof but not washdown-rated. The gearbox is lubricated for life, so no maintenance oil changes, which saves a headache on a hard-to-reach conveyor drive.
Obsolete — sourcing the GBX0600050851G today
Schneider has marked the GBX0600050851G as obsolete. That means no new production from the factory. The only channel for this part is independent surplus or broker stock — quantities are lot-specific and confirmed at RFQ. If you're supporting an existing line that uses this gearbox, the 30,000-hour service life at 100 rpm gives you a rough timeline for when spares will be needed. At higher speeds or loads, that life drops. The axial and radial force limits are 450 N / 340 N at 100 rpm for the full 30,000-hour life, or 600 N / 500 N for a shorter 10,000-hour life — useful if you're running the gearbox near its mechanical limits and need to plan the spares budget.