Calculate nominal speed and torque, compare right-angle options, and verify model-specific ratings. Results are screening estimates, not a model rating.
Quick estimate only. Enter the model’s efficiency when known; verify exact ratings with the manufacturer.
Ratio alone does not establish a worm reducer’s self-locking behavior. For its helical-worm units, SEW-EURODRIVE says the static criterion depends on forward efficiency and warns that self-locking must not be the sole safety function for hoists. Use a separately rated holding brake where the application requires one.
Continuous operation can be limited by heat balance. Compare the selected reducer’s thermal rating with the actual operating conditions; a different topology is an option to evaluate, not an automatic fix.
A catalog value is meaningful only with its definition and test condition. State whether the requirement is lost motion or backlash, the measurement load, and the new or end-of-life limit; request the same basis from every supplier.
Public sources support these directional comparisons, but do not establish one cross-brand efficiency, backlash, cost, or life value for each topology. The calculator therefore requires an explicit efficiency assumption and labels its outputs as screening estimates.
A nominal ratio does not determine a reducer’s efficiency, backlash, capacity, or safety behavior. Compare exact model data on a common measurement basis before selecting a topology.
| Topology | Published evidence | Verify before selection |
|---|---|---|
| Worm gear | Bonfiglioli states worm efficiency depends on tooth helix angle, speed, and running-in; do not use a generic percentage as a model rating. | Confirm rated torque, thermal capacity, starts per hour, permitted duty, backlash, and whether an independent brake is needed. |
| Hypoid gear | Sumitomo lists a 5:1–1440:1 HYPONIC family range, but its 2026 catalog’s up-to-93% efficiency statement begins at 30:1. Do not carry that figure into a 20:1 comparison. | Verify the exact 20:1 model’s available frame, efficiency, rated torque, backlash, thermal rating, and mounting limits. |
| Spiral bevel + planetary | Stage ratios multiply: 4:1 × 5:1 is a conceptual 20:1 combination, not evidence that a specific supplier offers that pairing. | Request stage-wise ratio, efficiency, backlash, torque, thermal, and torsional-stiffness ratings for the assembled unit. |
Need to compare a catalog rating with your application’s duty, backlash target, or mounting limits?
Request an exact 20:1 model checkA nominal 20:1 reducer divides input speed by about 20 and increases output torque subject to efficiency losses. Whether it fits depends on the load, duty, package, backlash, and safety requirements.
No. Worm, hypoid, and multi-stage right-angle arrangements are possible paths. Check a specific product catalog for the exact ratio, rated torque, efficiency, backlash, and thermal rating.
There is no single efficiency value for every 20:1 worm reducer. Use the selected model’s catalog data at the relevant speed, load, lubricant, and running-in condition.
It calculates motor torque from power and speed, then multiplies by 20 and the efficiency percentage you enter. It does not include the reducer’s rated capacity, service factor, or transient loads.
No. Compare the calculated demand with the exact model’s catalog rating and verify thermal capacity, duty, backlash, mounting, and any radial or axial output loads.
Do not assume it can from the ratio. Self-locking depends on the reducer and operating conditions, and it must not serve as the sole safety function for a hoist. Verify the application’s independent brake requirements.
Continue your technical evaluation or contact our team for a specific 20:1 sizing recommendation.
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