Sub 70 639 CB Irons Specifications
Full factory loft, lie and length chart for the Sub 70 639 CB irons, from 2019.
- Years produced
- from 2019
- Category
- Players Irons
- Construction
- forged from a billet with a CNC-milled back
- Material
- DT-4 soft steel
- Set makeup
- 3–PW
Loft, lie & length chart
| Club | Loft (°) | Lie (°) | Length (in) | Offset (in) | Bounce |
|---|---|---|---|---|---|
| 3 | 20 | 59.5 | 39 | 0.138 | 1 |
| 4 | 22 | 60 | 38.5 | 0.118 | 1 |
| 5 | 25 | 60.5 | 38 | 0.108 | 2 |
| 6 | 28 | 61 | 37.5 | 0.098 | 3 |
| 7 | 32 | 61.5 | 37 | 0.089 | 3.5 |
| 8 | 36 | 62 | 36.5 | 0.089 | 4 |
| 9 | 40 | 62.5 | 36 | 0.079 | 4.5 |
| PW | 44 | 63 | 35.75 | 0.069 | 5 |
Lofts and lies are the factory standard build. Individual clubs may differ if they have been bent, re-shafted or re-gripped during their life.
About the Sub 70 639 CB
The 639 CB was the players cavity back in the first forged iron family from Sub 70, the direct-to-consumer maker in Sycamore, Illinois, released in July 2019 alongside the 639 MB blade. Each head starts as a solid billet of what Sub 70's copy calls DT-4 soft stainless steel, is precision forged, and gets a custom-milled back; a rounded leading edge and sole are ground in for cleaner turf interaction. Lofts are traditional — a 32-degree 7-iron and a 44-degree pitching wedge across the 3-PW chart — and the CB shares its lie chart with the 639 MB so the two blend into combo sets. The 659 CB of 2022 was designed as its successor with the same head size and offset, but Sub 70 has kept the 639 CB in the line alongside it, and the model was still sold in satin and raw finishes as of a May 2025 site capture, so no discontinuation year is recorded.
Related models
Frequently asked questions
What is the loft of a Sub 70 639 CB 7-iron?
The Sub 70 639 CB 7-iron has a loft of 32 degrees, a lie of 61.5 degrees and a standard steel length of 37 inches.
Is the Sub 70 639 CB forged?
Yes. Each head starts as a solid billet of DT-4 soft steel, is precision forged, and is finished with a custom-milled cavity back.
Is the Sub 70 639 CB discontinued?
No. The 659 CB was launched in 2022 as its successor with the same head size and offset, but Sub 70 kept the 639 CB in its range, and it was still listed in the company's iron lineup as of May 2025.
Can the Sub 70 639 CB be combined with the 639 MB?
Yes. The 639 CB and 639 MB share the same lie chart and lengths, and Sub 70 sold factory MB/CB combo sets with cavity backs in the long irons and blades in the scoring clubs.
Buying a set
Sub 70 has since introduced the Sub 70 659 CB above it in the range, so the 639 CB is at the end of its retail life rather than fully retired — closeout sets still turn up at retailers while stock lasts, and it is well represented used on eBay, 2nd Swing and Golf Avenue. Check the loft and lie against the chart above before buying a used set: irons are routinely bent from standard during a fitting.
- Sub 70 official 639 CB Irons product page (golfsub70.com/sub-70-639-cb-irons.html, archive.org capture of 26 January 2021) — full specification table for 3-iron through PW: loft, lie, offset in millimetres (3.5 down to 1.75, converted to inches here), bounce, head weights 242 to 292 g, standard steel lengths 39 to 35.75 inches (graphite listed 0.5 inch longer), DT-4 steel material and Brushed Chrome finish, plus the billet-forged, custom-milled-back construction copy. The steel lengths are recorded as the standard spec.
- MyGolfSpy 'Sub 70 Irons: Model By Model' — 639 CB release date of July 2019, players cavity-back positioning; consistent with the earliest archive.org captures of the product page from 21 July 2019.
- Sub 70 official 659 CB product copy (2022) — states the 659 CB keeps the same head size and offset as the 639 CB with more mass low in the head, establishing the successor field.
- Note: year_discontinued is null because Sub 70 kept the 639 CB on sale after the 659 family launched in May 2022 — the model still appears in the golfsub70.com iron lineup on an archive.org capture of 14 May 2025. Sub 70 builds every set to order from a large no-upcharge shaft and grip menu, so no stock shaft is recorded. Sub 70's own copy calls the material 'DT-4 soft stainless steel'; its 659-era pages describe DT-4 as a soft carbon steel.
Last reviewed 2026-07-28. Spot an error? [email protected]