Specification
Where to buy| Item | Value |
|---|---|
| Type | Twist drill, jobber length |
| Material | HSCo (M-33 or M-42) |
| Finish | Bronze oxide standard; optional finishes may be specified by the customer |
| Maker | Precision brand, Dormer Pramet |
| Standard | Manufactured to NAS 907 Type J |
| Point | P-3 (135°) split point, heavy duty |
| Item | Value |
|---|---|
| Web | Thickness increases uniformly at a 0.006" ± 0.002" per inch taper |
| Size range | Ø1/16" thru Ø1/2" in the maker's NAS summary; its tables run #80 to 11/16" |
| Shank options | Straight, straight with tri-flats, quick change, reduced shank, reduced shank with tri-flats, tang |
| Lengths | Jobber length standard, 6" and 12" aircraft extension lengths optional |
| Status | Maker's aerospace brochure, read 30 Oct 2026; the NAS itself is not reproduced here. Check the current issue before you order. |
Part numbers
| Part no. | Size | Decimal, in | Ø mm (converted) | Flute l2, in | Overall l1, in | Overall, mm (converted) |
|---|---|---|---|---|---|---|
| 018380 | #80 | 0.0135 | 0.34 | 1/8 | 3/4 | 19.1 |
| 018379 | #79 | 0.0145 | 0.37 | 1/8 | 3/4 | 19.1 |
| 010301 | 1/64" | 0.0156 | 0.40 | 3/16 | 3/4 | 19.1 |
| 018378 | #78 | 0.0160 | 0.41 | 3/16 | 7/8 | 22.2 |
| 018377 | #77 | 0.0180 | 0.46 | 3/16 | 7/8 | 22.2 |
| 018376 | #76 | 0.0200 | 0.51 | 3/16 | 7/8 | 22.2 |
| 018375 | #75 | 0.0210 | 0.53 | 1/4 | 1 | 25.4 |
| 018374 | #74 | 0.0225 | 0.57 | 1/4 | 1 | 25.4 |
| 018373 | #73 | 0.0240 | 0.61 | 5/16 | 1-1/8 | 28.6 |
| 018372 | #72 | 0.0250 | 0.64 | 5/16 | 1-1/8 | 28.6 |
| 018371 | #71 | 0.0260 | 0.66 | 3/8 | 1-1/4 | 31.8 |
| 018370 | #70 | 0.0280 | 0.71 | 3/8 | 1-1/4 | 31.8 |
| 018369 | #69 | 0.0292 | 0.74 | 1/2 | 1-3/8 | 34.9 |
| 018368 | #68 | 0.0310 | 0.79 | 1/2 | 1-3/8 | 34.9 |
| 010302 | 1/32" | 0.0313 | 0.80 | 1/2 | 1-3/8 | 34.9 |
| 018367 | #67 | 0.0320 | 0.81 | 1/2 | 1-3/8 | 34.9 |
| 018366 | #66 | 0.0330 | 0.84 | 1/2 | 1-3/8 | 34.9 |
| 018365 | #65 | 0.0350 | 0.89 | 5/8 | 1-1/2 | 38.1 |
| 018364 | #64 | 0.0360 | 0.91 | 5/8 | 1-1/2 | 38.1 |
| 018363 | #63 | 0.0370 | 0.94 | 5/8 | 1-1/2 | 38.1 |
| 018362 | #62 | 0.0380 | 0.97 | 5/8 | 1-1/2 | 38.1 |
| 018361 | #61 | 0.0390 | 0.99 | 11/16 | 1-5/8 | 41.3 |
| 018360 | #60 | 0.0400 | 1.02 | 11/16 | 1-5/8 | 41.3 |
| 018359 | #59 | 0.0410 | 1.04 | 11/16 | 1-5/8 | 41.3 |
| 018358 | #58 | 0.0420 | 1.07 | 11/16 | 1-5/8 | 41.3 |
| 018357 | #57 | 0.0430 | 1.09 | 3/4 | 1-3/4 | 44.5 |
| 018356 | #56 | 0.0465 | 1.18 | 3/4 | 1-3/4 | 44.5 |
| 010303 | 3/64" | 0.0469 | 1.19 | 3/4 | 1-3/4 | 44.5 |
| 018355 | #55 | 0.0520 | 1.32 | 7/8 | 1-7/8 | 47.6 |
| 018354 | #54 | 0.0550 | 1.40 | 7/8 | 1-7/8 | 47.6 |
| 018353 | #53 | 0.0595 | 1.51 | 7/8 | 1-7/8 | 47.6 |
| 010304 | 1/16" | 0.0625 | 1.59 | 7/8 | 1-7/8 | 47.6 |
| 018352 | #52 | 0.0635 | 1.61 | 7/8 | 1-7/8 | 47.6 |
| 018351 | #51 | 0.0670 | 1.70 | 1 | 2 | 50.8 |
| 018350 | #50 | 0.0700 | 1.78 | 1 | 2 | 50.8 |
| 018349 | #49 | 0.0730 | 1.85 | 1 | 2 | 50.8 |
| 018348 | #48 | 0.0760 | 1.93 | 1 | 2 | 50.8 |
| 010305 | 5/64" | 0.0781 | 1.98 | 1 | 2 | 50.8 |
| 018347 | #47 | 0.0785 | 1.99 | 1 | 2 | 50.8 |
| 018346 | #46 | 0.0810 | 2.06 | 1-1/8 | 2-1/8 | 54.0 |
| 018345 | #45 | 0.0820 | 2.08 | 1-1/8 | 2-1/8 | 54.0 |
| 018344 | #44 | 0.0860 | 2.18 | 1-1/8 | 2-1/8 | 54.0 |
| 018343 | #43 | 0.0890 | 2.26 | 1-1/4 | 2-1/4 | 57.2 |
| 018342 | #42 | 0.0935 | 2.37 | 1-1/4 | 2-1/4 | 57.2 |
| 010306 | 3/32" | 0.0938 | 2.38 | 1-1/4 | 2-1/4 | 57.2 |
| 018341 | #41 | 0.0960 | 2.44 | 1-3/8 | 2-3/8 | 60.3 |
| 018340 | #40 | 0.0980 | 2.49 | 1-3/8 | 2-3/8 | 60.3 |
| 018339 | #39 | 0.0995 | 2.53 | 1-3/8 | 2-3/8 | 60.3 |
| 018338 | #38 | 0.1015 | 2.58 | 1-7/16 | 2-1/2 | 63.5 |
| 018337 | #37 | 0.1040 | 2.64 | 1-7/16 | 2-1/2 | 63.5 |
| 018336 | #36 | 0.1065 | 2.71 | 1-7/16 | 2-1/2 | 63.5 |
| 010307 | 7/64" | 0.1094 | 2.78 | 1-1/2 | 2-5/8 | 66.7 |
| 018335 | #35 | 0.1100 | 2.79 | 1-1/2 | 2-5/8 | 66.7 |
| 018334 | #34 | 0.1110 | 2.82 | 1-1/2 | 2-5/8 | 66.7 |
| 018333 | #33 | 0.1130 | 2.87 | 1-1/2 | 2-5/8 | 66.7 |
| 018332 | #32 | 0.1160 | 2.95 | 1-5/8 | 2-3/4 | 69.9 |
| 018331 | #31 | 0.1200 | 3.05 | 1-5/8 | 2-3/4 | 69.9 |
| 010308 | 1/8" | 0.1250 | 3.17 | 1-5/8 | 2-3/4 | 69.9 |
| 018330 | #30 | 0.1285 | 3.26 | 1-5/8 | 2-3/4 | 69.9 |
| 018329 | #29 | 0.1360 | 3.45 | 1-3/4 | 2-7/8 | 73.0 |
| 018328 | #28 | 0.1405 | 3.57 | 1-3/4 | 2-7/8 | 73.0 |
| 010309 | 9/64" | 0.1406 | 3.57 | 1-3/4 | 2-7/8 | 73.0 |
| 018327 | #27 | 0.1440 | 3.66 | 1-7/8 | 3 | 76.2 |
| 018326 | #26 | 0.1470 | 3.73 | 1-7/8 | 3 | 76.2 |
| 018325 | #25 | 0.1495 | 3.80 | 1-7/8 | 3 | 76.2 |
| 018324 | #24 | 0.1520 | 3.86 | 2 | 3-1/8 | 79.4 |
| 018323 | #23 | 0.1540 | 3.91 | 2 | 3-1/8 | 79.4 |
| 010310 | 5/32" | 0.1563 | 3.97 | 2 | 3-1/8 | 79.4 |
| 018322 | #22 | 0.1570 | 3.99 | 2 | 3-1/8 | 79.4 |
| 018321 | #21 | 0.1590 | 4.04 | 2-1/8 | 3-1/4 | 82.6 |
| 018320 | #20 | 0.1610 | 4.09 | 2-1/8 | 3-1/4 | 82.6 |
| 018319 | #19 | 0.1660 | 4.22 | 2-1/8 | 3-1/4 | 82.6 |
| 018318 | #18 | 0.1695 | 4.31 | 2-1/8 | 3-1/4 | 82.6 |
| 010311 | 11/64" | 0.1719 | 4.37 | 2-1/8 | 3-1/4 | 82.6 |
| 018317 | #17 | 0.1730 | 4.39 | 2-3/16 | 3-3/8 | 85.7 |
| 018316 | #16 | 0.1770 | 4.50 | 2-3/16 | 3-3/8 | 85.7 |
| 018315 | #15 | 0.1800 | 4.57 | 2-3/16 | 3-3/8 | 85.7 |
| 018314 | #14 | 0.1820 | 4.62 | 2-3/16 | 3-3/8 | 85.7 |
| 018313 | #13 | 0.1850 | 4.70 | 2-5/16 | 3-1/2 | 88.9 |
| 010312 | 3/16" | 0.1875 | 4.76 | 2-5/16 | 3-1/2 | 88.9 |
| 018312 | #12 | 0.1890 | 4.80 | 2-5/16 | 3-1/2 | 88.9 |
| 018311 | #11 | 0.1910 | 4.85 | 2-5/16 | 3-1/2 | 88.9 |
| 018310 | #10 | 0.1935 | 4.91 | 2-7/16 | 3-5/8 | 92.1 |
| 018309 | #9 | 0.1960 | 4.98 | 2-7/16 | 3-5/8 | 92.1 |
| 018308 | #8 | 0.1990 | 5.05 | 2-7/16 | 3-5/8 | 92.1 |
| 018307 | #7 | 0.2010 | 5.11 | 2-7/16 | 3-5/8 | 92.1 |
| 010313 | 13/64" | 0.2031 | 5.16 | 2-7/16 | 3-5/8 | 92.1 |
| 018306 | #6 | 0.2040 | 5.18 | 2-1/2 | 3-3/4 | 95.3 |
| 018305 | #5 | 0.2055 | 5.22 | 2-1/2 | 3-3/4 | 95.3 |
| 018304 | #4 | 0.2090 | 5.31 | 2-1/2 | 3-3/4 | 95.3 |
| 018303 | #3 | 0.2130 | 5.41 | 2-1/2 | 3-3/4 | 95.3 |
| 010314 | 7/32" | 0.2188 | 5.56 | 2-1/2 | 3-3/4 | 95.3 |
| 018302 | #2 | 0.2210 | 5.61 | 2-5/8 | 3-7/8 | 98.4 |
| 018301 | #1 | 0.2280 | 5.79 | 2-5/8 | 3-7/8 | 98.4 |
| 015301 | A | 0.2340 | 5.94 | 2-5/8 | 3-7/8 | 98.4 |
| 010315 | 15/64" | 0.2344 | 5.95 | 2-5/8 | 3-7/8 | 98.4 |
| 015302 | B | 0.2374 | 6.03 | 2-3/4 | 4 | 101.6 |
| 015303 | C | 0.2421 | 6.15 | 2-3/4 | 4 | 101.6 |
| 015304 | D | 0.2461 | 6.25 | 2-3/4 | 4 | 101.6 |
| 015305 | E | 0.2500 | 6.35 | 2-3/4 | 4 | 101.6 |
| 010316 | 1/4" | 0.2500 | 6.35 | 2-3/4 | 4 | 101.6 |
| 015306 | F | 0.2571 | 6.53 | 2-7/8 | 4-1/8 | 104.8 |
| 015307 | G | 0.2610 | 6.63 | 2-7/8 | 4-1/8 | 104.8 |
| 010317 | 17/64" | 0.2656 | 6.75 | 2-7/8 | 4-1/8 | 104.8 |
| 015308 | H | 0.2661 | 6.76 | 2-7/8 | 4-1/8 | 104.8 |
| 015309 | I | 0.2720 | 6.91 | 2-7/8 | 4-1/8 | 104.8 |
| 015310 | J | 0.2772 | 7.04 | 2-7/8 | 4-1/8 | 104.8 |
| 015311 | K | 0.2811 | 7.14 | 2-15/16 | 4-1/4 | 108.0 |
| 010318 | 9/32" | 0.2813 | 7.15 | 2-15/16 | 4-1/4 | 108.0 |
| 015312 | L | 0.2902 | 7.37 | 2-15/16 | 4-1/4 | 108.0 |
| 015313 | M | 0.2949 | 7.49 | 3-1/16 | 4-3/8 | 111.1 |
| 010319 | 19/64" | 0.2969 | 7.54 | 3-1/16 | 4-3/8 | 111.1 |
| 015314 | N | 0.3020 | 7.67 | 3-1/16 | 4-3/8 | 111.1 |
| 010320 | 5/16" | 0.3125 | 7.94 | 3-3/16 | 4-1/2 | 114.3 |
| 015315 | O | 0.3161 | 8.03 | 3-3/16 | 4-1/2 | 114.3 |
| 015316 | P | 0.3228 | 8.20 | 3-5/16 | 4-5/8 | 117.5 |
| 010321 | 21/64" | 0.3281 | 8.33 | 3-5/16 | 4-5/8 | 117.5 |
| 015317 | Q | 0.3319 | 8.43 | 3-7/16 | 4-3/4 | 120.7 |
| 015318 | R | 0.3390 | 8.61 | 3-7/16 | 4-3/4 | 120.7 |
| 010322 | 11/32" | 0.3437 | 8.73 | 3-7/16 | 4-3/4 | 120.7 |
| 015319 | S | 0.3480 | 8.84 | 3-1/2 | 4-7/8 | 123.8 |
| 015320 | T | 0.3580 | 9.09 | 3-1/2 | 4-7/8 | 123.8 |
| 010323 | 23/64" | 0.3594 | 9.13 | 3-1/2 | 4-7/8 | 123.8 |
| 015321 | U | 0.3680 | 9.35 | 3-5/8 | 5 | 127.0 |
| 010324 | 3/8" | 0.3750 | 9.52 | 3-5/8 | 5 | 127.0 |
| 015322 | V | 0.3772 | 9.58 | 3-5/8 | 5 | 127.0 |
| 015323 | W | 0.3858 | 9.80 | 3-3/4 | 5-1/8 | 130.2 |
| 010325 | 25/64" | 0.3906 | 9.92 | 3-3/4 | 5-1/8 | 130.2 |
| 015324 | X | 0.3969 | 10.08 | 3-3/4 | 5-1/8 | 130.2 |
| 015325 | Y | 0.4039 | 10.26 | 3-7/8 | 5-1/4 | 133.4 |
| 010326 | 13/32" | 0.4063 | 10.32 | 3-7/8 | 5-1/4 | 133.4 |
| 015326 | Z | 0.4130 | 10.49 | 3-7/8 | 5-1/4 | 133.4 |
| 010327 | 27/64" | 0.4219 | 10.72 | 3-15/16 | 5-3/8 | 136.5 |
| 010328 | 7/16" | 0.4375 | 11.11 | 4-1/16 | 5-1/2 | 139.7 |
| 010329 | 29/64" | 0.4531 | 11.51 | 4-3/16 | 5-5/8 | 142.9 |
| 010330 | 15/32" | 0.4687 | 11.90 | 4-5/16 | 5-3/4 | 146.1 |
| 010331 | 31/64" | 0.4844 | 12.30 | 4-3/8 | 5-7/8 | 149.2 |
| 010332 | 1/2" | 0.5000 | 12.70 | 4-1/2 | 6 | 152.4 |
| 010333 | 33/64" | 0.5156 | 13.10 | 4-13/16 | 6-5/8 | 168.3 |
| 010334 | 17/32" | 0.5313 | 13.50 | 4-13/16 | 6-5/8 | 168.3 |
| 010335 | 35/64" | 0.5469 | 13.89 | 4-13/16 | 6-5/8 | 168.3 |
| 010336 | 9/16" | 0.5625 | 14.29 | 4-13/16 | 6-5/8 | 168.3 |
| 010337 | 37/64" | 0.5781 | 14.68 | 4-13/16 | 6-5/8 | 168.3 |
| 010338 | 19/32" | 0.5937 | 15.08 | 5-3/16 | 7-1/8 | 181.0 |
| 010339 | 39/64" | 0.6094 | 15.48 | 5-3/16 | 7-1/8 | 181.0 |
| 010340 | 5/8" | 0.6250 | 15.88 | 5-3/16 | 7-1/8 | 181.0 |
| 010341 | 41/64" | 0.6406 | 16.27 | 5-3/16 | 7-1/8 | 181.0 |
| 010342 | 21/32" | 0.6563 | 16.67 | 5-3/16 | 7-1/8 | 181.0 |
| 010343 | 43/64" | 0.6719 | 17.07 | 5-5/8 | 7-5/8 | 193.7 |
| 010344 | 11/16" | 0.6875 | 17.46 | 5-5/8 | 7-5/8 | 193.7 |
Every fractional, wire gauge and letter size in the brochure, each with its order number (EDP).
What each code means
| Part | Meaning |
|---|---|
| R10CO | Series: Fractional sizes, 1/64" to 11/16" |
| R18CO | Series: Wire gauge sizes, #80 to #1 |
| R15CO | Series: Letter sizes, A to Z |
| Example | 018330 — #30, decimal 0.1285 in, series R18CO |
Notes
- Inch values are the maker's and are the official ones. Millimetres marked as converted are inches × 25.4.
- Catalogue items linked to this sheet match it by type: the seller's listing does not name this maker, so check the listing before you take a value from here.
- No split point on these sizes: #80, #79, 1/64", #78, #77, #76, #75, #74, #73, #72, #71, #70, #69, #68, 1/32", #67, #66, #65, #64, #63, #62, #61.
- The brochure's metric series 2ACO is made to DIN 338, not NAS 907, and is left out of this sheet.
Where to buy
AmericaDistributor coming soonOur partner for this region is on its way
EuropeDistributor coming soonOur partner for this region is on its way
OceaniaDistributor coming soonOur partner for this region is on its way
Distributors coming soon.
Sources
- Dormer Pramet Precision brochure — Drills Manufactured to National Aerospace Standards (NAS), pages 10 to 14 and 36 — sizes, lengths and order numbers, and the maker's summary of NAS 907 Type J. The maker's brochure, in a copy hosted for distributors.
Educational reference only. not approved data. Always consult the applicable SRM, AMM, or AC 43.13-1B and your certifying authority.