HF721 → TQ21H replacement

Replacement referenceDirectional lookup

Existing / searched modelBoston GearHF721Open source-model record →

Published target modelToledo GearTQ21HOpen target specs →

What the source establishesFunctional interchange

Toledo Gear publishes TQ21H at 2.06 in center distance for c-face or shaft input / hollow bore output and lists the competitor models in the same TG-90 interchange row. Toledo describes TG-90 reducers as designed to be functionally interchangeable while requiring current rating and dimensional verification.

Evidence meaning

The manufacturer describes the target family as functionally interchangeable with the listed competitor model or configuration.

Boston Gear HF721 and Toledo Gear TQ21H are tied by the published source at Match installed ratio · 2.06 in center distance.

Evidence boundary

The source still requires ratings, dimensions, ratio, fit, and application conditions to be checked before ordering.

Published target specifications3 model-level fields

Toledo GearTQ21HTG-90

Full model record →

Center distance: 2.06 inSource ↗
Configuration: C-Face or shaft input / hollow bore outputSource ↗
Interchange basis: Toledo TG-90 Interchange GuideSource ↗

Other models in the same published row9

Replacement verification checklistBefore purchase

RatioConfirm nominal and actual ratio against required output speed.

Shaft / boreMeasure the driven shaft and verify bushing or bore configuration.

InputCheck high-speed shaft, motor frame, sheave and input interface.

MountingCompare center height, footprint, torque-arm geometry and housing clearances.

AccessoriesDo not assume existing backstops, motor mounts, belt guards or screw-conveyor hardware transfer.

DutyRecheck torque, service factor, shock, starts per hour, temperature and lubrication.

Boston Gear HF721 replacement