One of the most confusing and annoying plumbing problems is replacing the bathtub drain (called a plug) that screws into the base (called a shoe). There are two common thread types (16 and 11 1/2 Threads Per Inch), and one uncommon one (14 TPI). We sell a variety of shoe adapters, some are only available from us.
| OD/strong> | TPI | Brand |
|---|---|---|
| 1 1/4 | 16 | |
| 1 3/8 | 16 | |
| 1 1/2 | 11 1/2 | American Standard, Central Brass, Gerber, Price Pfister |
| 1 13/16 | 14 | Crane / Sayco |
| 1 7/8 | 11 1/2 | |
| 2 1/16 | 16 | Kohler |
| 2 1/4 | 14 | |
| 2 1/4 | 16 |
| Part No. | OD | TPI | ID | TPI | Composition | Price |
|---|---|---|---|---|
| BW182250 | 1-3/4 16T | 1-5/8 16T | Brass | $14 |
| KIS58-7184 | 1 13/16 14T | 1 13/16 | Brass | $11 |
| ? | 2-1/4 | 1-1/2 | Brass | $16.00 |
| BW106510 | 2-1/4 16T | 1-5/8 16T | Brass | $20.00 |
1-3/8 in. NPSM (1-5/8 in. x 16 UNC) fine-thread body exterior
1-1/2 in. NPSM (1-7/8 in. – 11-1/2 UNC)
NPSM – American National Straight Pipe Thread for Mechanical Joints
TPI – Threads Per Inch
UNC – Unified Coarse Thread