Computer Tuned Propellers •  Marine Hardware

800.804.7757

410.867.8878

ISO TOLERANCES

Surprisingly, in the United States there are no industry-wide standards for the manufacture or repair of propellers.  This being the case,

Digital Prop Shop has adopted portions of the International Organization for Standardization (ISO) 484/2 standard to determine target tolerances for the propellers that we repair and tune.  The ISO 484/2 Accuracy Classes and Pitch/Position Tolerances to which we adhere are summarized in the following charts.

Our "Shop Standard" is Class I  Tolerances, as we feel this offers our customers the best price/performance value.  We will provide you with an easy to read color report which rates your propeller relative to these tolerances both before and after the work is performed.

ISO 484/2 Accuracy Classes:

Manufacturing Accuracy

Very High Accuracy

High Accuracy

Medium Accuracy

Wide Tolerances

Class

S

I

II

III

ISO 484/2 Pitch & Position Tolerances:

Class

Local Pitch

Mean Pitch per Radius

Mean Pitch per Blade

Mean Pitch per Propeller

Angular Deviation

Axial Position

S

± 1.50 %

± 1.00 %

± 0.75 %

± 0.50 %

± 1.00 %

± 0.50 %

I

± 2.00 %

± 1.50 %

± 1.00 %

± 0.75 %

± 1.00 %

± 1.00 %

II

± 3.00 %

± 2.00 %

± 1.50 %

± 1.00 %

± 2.00 %

± 1.50 %

III

 

± 5.00 %

± 4.00 %

± 3.00 %

± 2.00 %

± 3.00 %