GearCALC SplineCALCOndrives Gear Tools v14.11.3

Gear inspection symbols explained visually

Use the corrected Ondrives diagrams below to explore profile, lead, pitch, runout, tooth-thickness and microgeometry terminology. Select a diagram to enlarge it, or use the deviation explorer to see how the common profile, lead and pitch quantities are represented.

Important: this page is an educational reference. Final acceptance must always be checked against the drawing, purchase specification and the applicable inspection standard.
Interactive deviation explorer

Profile and lead show LF and RF of the same Gap 1. Profile +/− follows the inspection orientation. Lead defaults to METAL (Standard); select DIN to reverse the RF lead sign orientation.

0Total profile deviation Fα, µm
0Slope component fHα, µm
0Form component ffα, µm

How the symbols appear on inspection reports

Profile and lead report example

Example profile and lead inspection reportClick to enlarge

Hover the symbols for a quick explanation. Click the report to open a larger inspection-report view.

Pitch, runout and tooth-thickness report example

Example pitch, runout and tooth thickness inspection reportClick to enlarge

Pitch is shown using report-style bars in the deviation explorer, matching the way discrete tooth results are normally presented.

Gear quality grades & standard comparison

Compare the quality-grade systems used across Ondrives drawings, catalogues and inspection references. The table keeps the legacy DIN / ISO / AGMA relationships already used in Ondrives technical material and adds current JIS context.

Use as a comparison guide: grade numbers are not a universal one-to-one tolerance conversion for every gear size and every inspection characteristic. Final acceptance must be checked against the specified edition of the standard and the drawing.

ISO micron accuracy guide

Profile—Total profile Fα
—fHα
—ffα
Lead—Total lead Fβ
—fHβ
—ffβ
Pitch—Total cumulative pitch Fp
—fp
—Fr
Guide values: these micron figures use the ISO 1328-1:1995/97 formula-and-grade scaling structure previously used in the Ondrives quality tool. They are a quick engineering comparison, not a substitute for the applicable licensed standard or drawing acceptance limits.

Quality-grade comparison

Numbering: DIN / ISO / modern AGMA A / JIS run from lower number = tighter to higher number = broader. Legacy AGMA Q runs in the opposite direction. Ondrives comparison data used here is DIN/ISO 3–10 ↔ AGMA Q14–Q7.

Ondrives standard gear quality by family

Published catalogue/product quality for the main cylindrical gear families. Module 0.5 and 0.8 use the small-module DIN 58405 tolerance designation where shown; larger modules use DIN 3967 tooth-thickness tolerance designations.

Precision spur gears — metalGrade 7e at mn 0.5–0.8; Grade 7e25 from mn 1.0 upward. DIN 3961 with DIN 58405 / DIN 3967. AGMA comparison Q10.PSG steel, stainless, hardened and titanium families.
Precision spur gears — plasticGrade 8e at mn 0.5–0.8; Grade 8e25 from mn 1.0 upward. DIN 3961 with DIN 58405 / DIN 3967. AGMA comparison Q9.PSG-DL Delrin POM and PSG-PK PEEK GF30 families.
Parallel helical gearsGrade 7e at mn 0.5–0.8; Grade 7e25 from mn 1.0 upward. DIN 3961 with DIN 58405 / DIN 3967. AGMA comparison Q10.PHG 15° parallel helical range.
Ground spur gearsGrade 5f at mn 0.5–0.8; Grade 4f24 from mn 1.0 upward. DIN 3961 with DIN 58405 / DIN 3967; ISO 1328 referenced on larger-module products.UPSG ground spur range.
Ground helical gearsGrade 5f at mn 0.5–0.8; Grade 4f24 from mn 1.0 upward. DIN 3961 with DIN 58405 / DIN 3967; ISO 1328 referenced on larger-module products.UPHG ground parallel helical range.
Splined ground gearsPublished examples use Grade 4f24 DIN 3961 / 3967 (ISO 1328) for ground helical gears with DIN 5480 splined bores.UPHGS range; check the selected product page for exact module and spline.

Manufacturing process quality regions

Indicative regions from Ondrives technical material; final capability depends on geometry, size, material and inspection requirement.

GrindingApproximately grades 3–6.
HobbingApproximately grades 6–8.
ShapingApproximately grades 6–9.

Ondrives product example

1.25 mn module · 50 teeth · standard face-width spur gear

PSG1.25-50

PSG1.25-50 Precision Spur Gear

817M40T / AISI 4340 steel, 20° pressure angle, 1.25 normal module and 50 teeth.

Published quality: Grade 7e25 DIN 3961 / DIN 3967 · AGMA Q10 comparison.

Open PSG1.25-50 product page
Part number
PSG1.25-50
Quality
7e25
Standard
DIN 3961 / 3967
AGMA
Q10
Normal module
1.25
Teeth
50
Reference diameter
62.5 mm
Tip diameter
65 mm