Description
Is your thread size off by one size?
These black & gray nylon reducers will solve that threading problem. They convert holes which fit PG, NPT or Metric threads to a smaller female thread of the same thread type.
Dimensions
Dimensions tables are long and do not adequately fit on mobile devices.
View this page on a tablet or computer, or call Estco with questions about dimensions:

Reducers – PG to PG Threads | |||||||
PART NUMBERS | THREADS | ADAPTER TYPE | DIMENSIONS IN INCHES (mm) | ||||
Male Thread | Female Thread | T | H | D | W | ||
A | B | Thread Length | Height | Outer Diameter | Wrench Flat | ||
SR-RR-0907-GY | PG 9 | PG 7 | B | .31 (8) | .55 (14) | .75 (19) | N/A |
SR-RR-1109-GY | PG 11 | PG 9 | B | .31 (8) | .71 (18) | .89 (22.5) | N/A |
SR-RR-1309-GY | PG 13 | PG 9 | A | .31 (8) | .47 (12) | 1.06 (27) | N/A |
SR-RR-1311-GY | PG 13 | PG 11 | B | .35 (9) | .83 (21) | 1.0 (25.5) | N/A |
SR-RR-1609-GY | PG 16 | PG 9 | A | .39 (10) | .51 (13) | 1.14 (29) | N/A |
SR-RR-1611-GY | PG 16 | PG 11 | A | .39 (10) | .51 (13) | 1.14 (29) | N/A |
SR-RR-1613-GY | PG 16 | PG 13 | B | .39 (10) | .98 (25) | 1.13 (28.5) | N/A |
SR-RR-2113-GY | PG 21 | PG 13 | A | .43 (11) | .53 (13.5) | 1.42 (36) | N/A |
SR-RR-2116-GY | PG 21 | PG 16 | A | .43 (11) | .53 (13.5) | 1.42 (36) | N/A |
SR-RR-2921-GY | PG 29 | PG 21 | A | .43 (11) | .53 (13.5) | 1.81 (46) | N/A |
SR-RR-3629-GY | PG 36 | PG 29 | A | .43 (11) | .59 (15) | 2.28 (58) | N/A |
Reducers – Metric to Metric Threads | |||||||
PART NUMBERS | THREADS | ADAPTER TYPE | DIMENSIONS IN INCHES (mm) | ||||
Male Thread | Female Thread | T | H | D | W | ||
A | B | Thread Length | Height | Outer Diameter | Wrench Flat | ||
SR-RR-1612-GY | M16 x 1.5 | M12 x 1.5 | B | .35 (9) | 1.06 (27) | .87 (22) | .79 (20) |
SR-RR-2016-GY | M20 x 1.5 | M16 x 1.5 | B | .35 (9) | 1.06 (27) | 1.06 (27) | .94 (24) |
SR-RR-2520-GY | M25 x 1.5 | M20 x 1.5 | A | .39 (10) | .67 (17) | 1.26 (32) | 1.14 (29) |
SR-RR-3225-GY | M32 x 1.5 | M25 x 1.5 | A | .47 (12) | .75 (19) | 1.57 (40) | 1.42 (36) |
SR-RR-4032-GY | M40 x 1.5 | M32 x 1.5 | A | .47 (12) | .75 (19) | 2.01 (51) | 1.81 (46) |
SR-RR-5040-GY | M50 x 1.5 | M40 x 1.5 | A | .55 (14) | .83 (21) | 2.40 (61) | 2.17 (55) |
SR-RR-6350-GY | M63 x 1.5 | M50 x 1.5 | A | .59 (15) | .87 (22) | 2.95 (75) | 2.68 (68) |
Reducers – Metric to Metric Threads | |||||||
PART NUMBERS | THREADS | ADAPTER TYPE | DIMENSIONS IN INCHES (mm) | ||||
Male Thread | Female Thread | T | H | D | W | ||
A | B | Thread Length | Height | Outer Diameter | Wrench Flat | ||
SR-RM-1612-BK | M16 x 1.5 | M12 x 1.5 | C | .31 (8) | .55 (14) | .39 (10) | .79 (20) |
SR-RM-2016-BK | M20 x 1.5 | M16 x 1.5 | C | .31 (8) | .55 (14) | .53 (13.5) | .98 (25) |
SR-RM-2520-BK | M25 x 1.5 | M20 x 1.5 | C | .31 (8) | .55 (14) | .71 (18) | 1.14 (29) |
SR-RM-3225-BK | M32 x 1.5 | M25 x 1.5 | C | .39 (10) | .63 (16) | .91 (23) | 1.42 (36) |
SR-RM-4032-BK | M40 x 1.5 | M32 x 1.5 | D | .59 (15) | .79 (20) | 1.18 (30) | N/A |
SR-RM-5040-BK | M50 x 1.5 | M40 x 1.5 | D | .59 (15) | .79 (20) | 1.50 (38) | N/A |
SR-RM-6350-BK | M63 x 1.5 | M50 x 1.5 | D | .59 (15) | .79 (20) | 1.89 (48) | N/A |
Reducers – NPT to NPT Threads | ||||||
PART NUMBERS | THREADS | ADAPTER TYPE | DIMENSIONS IN INCHES (mm) | |||
Male Thread | Female Thread | T | H | D | ||
A | B | Thread Length | Height | Inner Diameter | ||
SR-RB-3412-02 | 3/4″ NPT | 1/2″ NPT | C | .637 (16.2) | .887 (22.5) | .696 (17.7) |
SR-RB-3438-02 | 3/4″ NPT | 3/8″ NPT | C | .625 (15.9) | .875 (22.2) | .696 (17.7) |
SR-RB-1012-02 | 1″ NPT | 1/2″ NPT | C | .65 (16.5) | .90 (22.9) | .91 (23.1) |
SR-RB-1034-02 | 1″ NPT | 3/4″ NPT | C | .65 (16.5) | .90 (22.9) | .92 (23.4) |
SR-RB-1214-02 | 1/2″ NPT | 1/4″ NPT | C | .566 (14.4) | .816 (20.7) | .56 (14.2) |
SR-RB-1238-02 | 1/2″ NPT | 3/8″ NPT | C | .574 (14.6) | .824 (20.9) | .561 (14.2) |