AGMA Member CompanySince 1946East Walpole, MA

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Quality Inspection

GEAR INSPECTION & QUALITY CONTROL

Quality Inspection for Machining and Gear Manufacturing

A gear can meet basic dimensions and still create noise, binding, poor contact, excessive backlash or premature failure in an assembly.

We provide specialized gear inspection, dimensional verification and gear troubleshooting for custom gears, sprockets, splines, racks and related machined components. Dedicated inspection equipment lets our team evaluate tooth profile, lead, composite error, tooth-to-tooth variation, runout, backlash, tooth bearing and dimensional features according to the component and customer requirements.

Inspection supports both sides of our work: verifying components we manufacture and investigating gears that are not performing as expected.

ITW PROFILE & LEAD · INSPECTION CHART

Three reasons customers use our inspection capability

Verify

Confirm critical gear and component characteristics against the drawing, purchase order and job requirements.

Diagnose

Investigate binding, noise, fit, runout, tooth-contact and other gear-performance problems.

Control

Establish a quality plan for new manufacturing work and follow the required inspection points through production.

Inspection starts with the requirements

A Quality Plan Starts With the Drawing

Inspection should not begin by choosing a measuring instrument. It begins by understanding what the component is required to do and what the customer has specified.

For a new job, a quality plan is developed around the customer’s part, drawing and purchase-order requirements and followed through the production process. The inspection methods therefore depend on the component — not one generic checklist applied to every gear.

What Defines the Inspection Plan?

The Component

A spur gear does not require the same inspection approach as a bevel gear, worm, spline, sprocket or rack. Tooth form and component geometry determine which characteristics can affect fit and operation.

The Drawing & Purchase Order

Dimensions, gear data, fit requirements, tolerances and customer-specified inspection requirements establish what must be verified.

The Mating Relationship

Some characteristics are best evaluated with the mating component. Our documented procedures call for mating-part checks on helical gears, worms, worm gears and splines.

Result

Job-Specific Quality Plan

Built around your part, drawing and purchase order — and followed through production.

Dimensional Inspection vs. Gear Inspection

Physical features

Dimensional Inspection

Evaluates physical component features such as bores, diameters, depths, tooth thickness, throat diameter and other drawing dimensions.

vs

How teeth generate and mesh

Specialized Gear Inspection

Evaluates the characteristics that determine how teeth are generated and how components mesh.

For components that combine CNC-machined features with gear teeth, both forms of verification may be important.

Different components require different checks

What We Inspect by Gear and Component Type

We maintain documented inspection procedures for individual gear and power-transmission component families — because what matters on a helical gear is not identical to what matters on a sprocket, bevel gear, worm or spline.

Select a component to see its documented inspection methods.

Composite + backlash

Spur Gears

Documented inspection methods:

Chain-wrap pitch

Sprockets

Documented inspection methods:

Mating-part check

Helical Gears

Documented inspection methods:

Internal pins

Internal Spur Gears

Documented inspection methods:

Contact pattern

Bevel & Miter Gears

Documented inspection methods:

Mating-part check

Worms

Documented inspection methods:

Bearing roll

Worm Gears

Documented inspection methods:

Tooth position

Ratchets

Documented inspection methods:

Straightness

Gear Racks

Documented inspection methods:

Gauge fit

Straight-Sided Splines

Documented inspection methods:

Gauge / mating fit

Involute Splines

Documented inspection methods:

These methods come from our published Inspection & Testing Procedures. They are general procedures that are incorporated into a more detailed, job-specific quality plan.

Inspection Characteristics Explained

Profile

Evaluates the geometry of the gear tooth profile.

Lead

Evaluates tooth direction across the face of the gear — particularly important for helical gearing.

Composite Inspection

Evaluates combined gear-tooth variation during rolling inspection, incorporating tooth-to-tooth error and runout.

Runout / T.I.R.

Evaluates variation as the component rotates relative to its reference.

Backlash

Evaluates clearance between mating teeth under the required assembly relationship.

Tooth Bearing / Contact Pattern

Shows where mating gear teeth make contact, helping identify conditions such as toe, heel or cross bearing.

Fit Inspection

For components such as splines, gauges or mating parts verify the required fit class.

Dedicated gear metrology & measurement

Gear Inspection Equipment

We maintain inspection equipment specifically intended for gear geometry, as well as equipment for dimensional and related component verification.

Tooth Geometry & Gear Error

Tooth geometry

ITW Profile Tester

Supports evaluation of gear tooth profile.

Tooth geometry

ITW Lead Tester

Supports lead inspection and identification of lead deviations.

Tooth geometry

ITW Composite Tester

Supports composite gear inspection, including tooth-to-tooth variation and runout characteristics.

Our ITW equipment helps identify profile deviations, lead deviations, pitch variations and radial runout. ITW profile, lead and composite inspection remains part of our active inspection capability in 2026.

Dedicated Gear Inspection

These systems expand our ability to evaluate gear geometry, involute characteristics, runout and related gear-specific requirements.

Bevel & Worm Gear Inspection

Dedicated support where mounting relationship, runout and tooth-bearing pattern are critical.

Dimensional & Supporting Inspection

Together, the inspection department supports both gear-specific metrology and dimensional component verification — rather than treating gear inspection as ordinary dimensional measurement alone.

When a gear measures wrong — or runs wrong

Gear Troubleshooting and Problem Diagnosis

Inspection becomes especially valuable when the question is not simply, “Does this part match the drawing?”

We accept gear problems for evaluation in addition to inspecting newly manufactured components — using measurement results to identify manufacturing problems and establish corrective quality plans.

Why is the assembly binding?

Why is the gear set noisy?

Why did the spline fail?

Is the problem profile, lead, runout, fit or tooth contact?

Case file 01

Helical Gears Binding

Problem
A rock-drill manufacturer approached us after helical gears from its existing supplier were binding in an assembly.
Inspection
We inspected the supplied components using Fellows lead and profile equipment. The inspection identified excessive lead and profile error.
Outcome
A quality plan was developed for the replacement manufacturing program.

Inspection focus

Case file 02

Excessive Noise in a Bevel Gear Assembly

Problem
A marine-pump manufacturer supplied bevel gears after experiencing excessive noise.
Inspection
We evaluated tooth contact on a calibrated Gleason center-distance checker and performed radial and axial runout testing. The inspection identified cross bearing from heel to toe and runout exceeding the backlash in the gear set.
Outcome
A quality plan was developed for manufacturing the components.

Inspection focus

Case file 03

Premature Spline Shaft Failure

Problem
A mining-equipment builder supplied failed spline shafts together with its drawings.
Inspection
Inspection against the drawing showed the previous supplier had manufactured side-fit splines while the drawing specified O.D.-fit splines.
Outcome
We developed a quality plan for the customer’s spline manufacturing requirements.

Inspection focus

What These Cases Demonstrate

The objective of gear troubleshooting is not simply to collect measurements. It is to connect the measurement to the drawing, mating relationship and actual performance problem so the manufacturing issue is understood before replacement parts are produced.

Inspection is part of the manufacturing process

Quality Control for Custom Gear Manufacturing

Inspection works best when it is connected directly to manufacturing.

We combine custom gear cutting, CNC machining and specialized inspection within the same operation — so inspection information supports the production process rather than being only a final check after the component is complete.

At the centre

The Job-Specific Quality Plan

Every checkpoint traces back to the drawing, purchase order and mating relationship.

Before Production

Review the drawing, purchase order, gear geometry, fit requirements and customer inspection requirements.

During Production

Apply the job-specific quality plan and verify the characteristics appropriate to the component and manufacturing stage.

After Gear Cutting

Evaluate required tooth and dimensional characteristics using the appropriate gear inspection and measurement equipment.

When a Problem Is Found

Inspection data identifies the condition, reviews the manufacturing process and establishes corrective action before the job proceeds.

For Mating Components

Where appropriate, inspection includes center-distance, backlash, bearing/contact or fit checks using the mating gear, worm, spline or related component.

Our documented procedures specifically use mating-component checks for several product families, including helical gears, worms, worm gears and splines.

Current Quality Positioning

Why Manufacturers Use Commercial Gear for Gear Inspection

Dedicated Gear Metrology

Inspection equipment designed specifically to evaluate gear characteristics — not only general dimensions.

Product-Specific Inspection Procedures

Spur gears, helicals, bevels, worms, sprockets, racks, ratchets and splines have documented inspection approaches.

Inspection Tied to Manufacturing

Measurement information can feed directly into CNC machining and gear-cutting operations.

Troubleshooting Experience

We investigate existing gear and assembly problems as well as newly manufactured components.

120+ Years of Combined Industry Experience

Experienced personnel evaluate measurement results in the context of the drawing, component and application.

Send us the drawing — or the problem

Request a Gear Inspection or Manufacturing Review

Evaluating a new gear manufacturing project, dealing with parts from an existing supplier, or trying to work out why a gear set is not performing? Send us the available information.

The more context we have about the part and the problem, the more useful the initial review can be.

What to Send

For a new manufacturing requirement

For a gear problem or failure

Gear inspection questions

Gear Inspection FAQ

Can’t find your answer? Call 800.491.1073 or send your drawing and we’ll help.

The required checks depend on the gear type and drawing. Our documented procedures include methods for evaluating measure over pins, tooth-to-tooth variation, profile, lead, composite error, runout, pitch, backlash, tooth bearing/contact and fit.

Profile inspection evaluates the shape of the tooth profile. Lead inspection evaluates tooth direction across the gear face. Composite inspection evaluates combined variation while the gear is rolled, including tooth-to-tooth error and runout.

Yes. We accept problem gears for inspection and correction. Our helical, bevel and spline case histories all involve evaluating components supplied by customers after problems with previous manufacturing sources.

Yes, when appropriate to the component. Our documented procedures include mating-component checks for helical gears, worms, worm gears and splines, including center-distance, backlash, tooth-bearing and fit evaluations.

Our bevel and miter gear procedures include checks for addendum, circular tooth thickness, depth, radial and axial runout, tooth-bearing/contact pattern, toe/heel/cross bearing and backlash at the required mounting distance.

Straight-sided spline procedures include root diameter, tooth thickness, runout and fit checks using a gauge or mating component. Involute spline procedures include measure over pins, runout and gauge or mating-component fit, with lead, profile and spacing evaluated when required.

Yes. We provide gear cutting, CNC machining and inspection, so job-specific inspection requirements are built into the manufacturing quality plan rather than handled only after production is complete.