A decimal copied into a comparison note can lose its most useful detail: the unit beside it. With these two AP2 charts, the 7-iron figures are nearly equivalent after conversion. The longer iron and pitching-wedge examples tell a different story, so a single matching row also needs the rest of the set for context.
Check the offset units first
Titleist's AP2 (712) specification tableprints offset in inches, using the inch mark after each value. Its 718 iron specification tablesprint offset in millimeters and include several head families on the same page. Read the OFFSET table, the AP2 row and the correct club-number column together.
Offset is listed as a length dimension in these charts. Keep it separate from the angles in the loft and lie tables, even when those values sit close together on the page. A note such as “7-iron offset: 0.110 in” retains the information needed for a later comparison; “offset: 0.110” leaves that comparison ambiguous.
Convert the 7-iron example
NIST defines one inch as exactly 25.4 millimeters. Multiply an inch value by 25.4 to express it in millimeters; divide a millimeter value by 25.4 to express it in inches.
0.110 in × 25.4 = 2.794 mm
Rounded to one decimal place, that calculation is 2.8 mm, the number printed for the 718 AP2 7-iron. The two published figures agree at that displayed precision. Reading 2.8 as though it were inches would produce a completely different comparison.
The extra digits in 2.794 come from arithmetic on the printed 0.110-inch figure. They add no evidence about manufacturing tolerances or the offset of an individual used head. Keep the original source figure beside the conversion so its precision stays visible.
Compare three clubs across the set
These selected rows come from the two linked US Titleist archives. The middle column is calculated here; the other numeric columns retain each manufacturer's published units and decimal places. “P” follows the pitching-wedge label in both charts.
| Club | AP2 (712), published (in) | AP2 (712), calculated (mm) | 718 AP2, published (mm) |
|---|---|---|---|
| 4-iron | 0.145 | 3.683 | 3.8 |
| 7-iron | 0.110 | 2.794 | 2.8 |
| P | 0.085 | 2.159 | 1.9 |
Once both columns use millimeters, the 4-iron has a higher published offset in the 718 chart, while P has a lower one. The near agreement at the 7-iron therefore supports a conclusion about that row alone. It does not establish that the offset sequence, head geometry or playing characteristics are identical.
For the other core specifications, open our separate AP2 (712) referenceand 718 AP2 reference. Their per-club charts cover loft, lie and playing length. Use the manufacturer links above for the offset values discussed here.
Keep a useful comparison record
- Identify the generation. Record the full model name and photograph its markings. Our older-iron identification guidehelps you choose the right archive.
- Save the source value and unit. Include the club label, manufacturer URL and the date you checked it. Keep any stated market or build context with the note.
- Convert into a separate column. Label it as a calculation and retain the source's original decimal places alongside it. Compare matching club labels across several rows.
- Record the actual clubs separately. If you have a physical measurement, save its method and date. Keep a factory-chart conversion labelled as factory information.
A used set's current build still needs its own evidence. The used-iron checklistcovers the questions to ask about changes and condition. Matching rounded offset numbers alone leaves distance, ball flight and suitability for a golfer unresolved.
Sources and limits
Reviewed October 3, 2026: Titleist's US AP2 (712) archive, the AP2 row in its 718 iron offset table, and NIST's SI Units – Length page. Only three selected offset rows are used here; this is a worked reading example rather than a reproduction of either complete chart.
The calculations describe published factory specifications. No heads were measured or tested for this article. The source tables and unit conversion establish no offset measurement protocol or tolerance for a used club. A good comparison note ends with the model, club, value, unit and source still attached.