AP Clutches Distributed by Stauffer Diesel Inc.



Torque Calculation:
Use these formulas and the appropriate safety factor to determine the correct clutch size for any application.
Clutch size requirement should be determined based on peak torque capability of the engine.


Safety Factor

Duty Classification Selection Guide

Extra Light Duty

Pumps - Centrifugal

Hydraulic Pumps
w/o priming

Irrigation Pumps

Light Duty

Cereal Dryers

Elevators - Bucket

Machines, general - all types with uniform loads,
non reversing

Medium Duty

Agitators - solid or semi solids

Blowers & fans
centrifugal & lobe.

Compressors - all
centrifugal, screw

Elevators - bucket, non-uniformly loaded or fed

Mixers - continuous

Pumps - two or more

conveyors - uniformly loaded
Dredge Pumps
(allow for shock loading)

Heavy Duty

Cranes & Hoist
- working clutch

Crushers - ore & stone

Chipper - wood

Drums - barking

Compressors - lobe rotary plus three or more cylinder reciprocal type.

Machines - impact load types

Mills - ball type

Mud pumps

Allowable Side Load

Allowable side-pull loads for PTO's.
The following formula should be used for determining the allowable side load "L" (lbs.).

L = 126,000 x HP x FL

N x D

L = Allowable side load (lbs.)
N = Shaft speed (RPM)
D = Pitch dia. of pulley, chain or gear (inches)
FL = Load factor
1.0 for single chain or gear
1.25 for double chain
1.5 for V-belt drive
2.0 for single ply belt
2.5 for double ply belt
3.0 for triple ply belt

Important: A support plate for double and triple 14" PTO's is required in side pull applications and is recommended for inline applications.

Stauffer Diesel Inc., Stadco

Home Office: 34 Stauffer Lane  Ephrata, PA 17522
Phone: 717-738-2500     Fax: 717-738-2550

Branch Office: 55 Billot Avenue  Irwin, PA 15642
Phone: 724-864-6969     Fax: 724-864-9392

Copyrighted 2001 Stauffer Diesel Inc.