
Why are there different Sheave Gauges formats?
In order to ensure optimal performance of sheaves and wire rope a complete range of sheave gauges should be used. We stock gauges in the following formats:
+2.5% API Sheave Gauges are used to determine when Maximum and Excessive Wear levels has been reached.
+5% Sheave Gauges are legacy format. They should fit snugly in new or re-machined sheaves. If correctly sized wire rope is run through the sheaves there will be a minimum of friction which should extend the life of the wire rope.
+6% API Sheave Gauges measures the minimum size for a new sheave.
+10% API Sheave Gauges measures the maximum size for a new sheave.
Other formats can be custom made upon request.
Measuring Sheave Wear
+10% Oversize New

When there is space on the sides of a +10% Gauge the sheave is too loose and should be remachined.
+10% Maximum New

A +10% Gauge, without any gaps on the bottom or sides, indicates the maximum diameter for a new sheave.
+10% Tight Fit

Use a +6% Gauge to check whether it meets minimum new sheave tolerances.
+6% Minimum New

Use a +10% Gauge to check whether it meets maximum new sheave tolerances.
+6% Minimum New

A +6% Sheave Gauge, without any gaps on the bottom or sides, indicates the minimum diameter for a new sheave.
+6% Tight Fit

Use a +2.5% Sheave Gauge to test if there is excessive wear.
+2.5% Maximum Wear

Test with a +6% Sheave Gauge to check whether it meets minimum new sheave tolerances.
+2.5% Maximum Wear

A +2.5% Gauge fitting without space on side or bottom, means it has reached its maximum wear point and should be scheduled for replacement.
+2.5% Excessive Wear

A gap below a +2.5% Sheave Gauge indicates an excessively worn Sheave which should be removed from service at the next opportunity.
Measuring Wire Rope
NOMINAL WIRE GAUGES

MEASURE ACROSS THE
OUTER EDGE OF TWO STRANDS

USE LARGER GAUGE

USE SMALLER GAUGE
Using a Nominal
Wire Rope Gauge
Only use a wire rope gauge to determine approximate wire rope diameter.
- Align the gauge so that the wire can be measured from the outer edge of one strand to the edge of the strand directly opposite.
- If the wire rope does not fit in the gauge, use a larger gauge until the wire rope fits in the gauge.
- Shine a light behind the gauge.
- If you can see light between the gauge and the wire rope, repeat with a smaller gauge until no light shows.
For more accurate measurements use a machinist’s caliper or micrometer.
GO NO/GO WIRE GAUGES

CORRECT
Wire Rope should not fit in Gauge

ROUGED WIRE ROPE
Replace if Cable Shows Rust

REPLACE WIRE ROPE
When Cable Fits in Gauge
Using a Go/NoGo
Wire Rope Gauge
Only use a wire rope gauge to determine approximate wire rope diameter.
- Align the gauge so that the wire can be measured from the outer edge of one strand to the edge of the strand directly opposite.
- If the wire rope does not fit in the gauge, it is still above the nominal -3.125% threshold.
- If the wire rope fits in the first notch, it should be replaced if the cable shows rust (rouge).
- If the wire rope reaches the bottom of the gauge, it should be replaced.
For more accurate measurements use a machinist’s caliper or micrometer.

Range Sets for API RP 9B Compliance
Ensure precision and reliability with our API RP 9B-compliant range sets. Designed for accurate sheave and wire rope wear assessment, these tools help maintain operational safety and performance.