Needle roller bearings NK, NKS, RNA4900 (NK10/16, NK20/20, RNA4904 and more): Fw, OD, width, r min + 14 ring-envelope STEP/STL files — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/needle-roller-bearings-nk-rna-nks/ (sheet CC BY 4.0) Basis: Koyo (JTEKT) machined needle roller catalogue rows (Fw, D, C, r min) checked against Emerson Bearing NK and RNA 4900 lists; Nose Seiko (JNS) used for the r min disagreement; McMaster-Carr needle bearings linked Catalog version: 2026-10-20 Sizes: see table below - NK, NKS and RNA bearings are machined-ring needle roller bearings without an inner ring: the needles run directly on a hardened shaft (or on an IR / LRT inner ring). Fw is the diameter of the circle inscribed to the needles, so the shaft or inner ring raceway must be Fw (tolerance F6-type fit, see the maker's catalogue). NK has a plain outer ring, NKS a wider-OD (heavier) ring, RNA49 and RNA69 the 49 and 69 dimension series (RNA69 is the wide one). With the matching inner ring they become NKI / NA. - Numbers: Koyo (JTEKT) machined-ring needle roller catalogue pages (Fw, D, C, r min). Independent check on Fw, D and C: Emerson Bearing's NK list (every one of the 25 rows read matches a Koyo row) and RNA 4900 list (the ten rows that Koyo also has agree, except RNA4906). Disagreements kept: RNA4906 is 18 mm wide in Koyo and 17 mm in Emerson; the four smallest rows NK5/10, NK5/12, NK6/10, NK6/12 have r min 0.2 in Koyo and 0.15 in Nose Seiko (JNS) (no file is made for them). Emerson's page lists NK5/10 under the name NK 5/12 TN (its C is 10). - RNA4907 to RNA4922 are Emerson-only rows (Fw, D, C, no r min); NK / NKS rows above NK40 were not read. The mid-size 'A' versions are the current ones; the Koyo table names are given as printed (A, TN and other suffixes only differ in cage or tolerance details that are not in this table). - Files: 14 ring envelopes with r min from Koyo (NK8/12, NK10/16TN, NK12/16, NK15/16A, NK20/20A, NK25/20A, NK30/30A, RNA4900, RNA4902, RNA4904, RNA4905, RNA6905A, NKS25A, RNA49/32): one solid ring, bore Fw, OD D, width C, corners rounded at r min. No needles, cage, oil hole or groove. - Left out: load ratings and speeds (the makers differ), NKI / NA with-inner-ring types (see the IR page for the rings), RNA48 and RNA59, NQ series, sizes above 40 mm shaft with r min, drawn-cup HK / BK (separate page). bearing roller-set bore Fw, mm OD D, mm width C, mm r min, mm source NK5/10TN 5 10 10 0.2 (Koyo) / 0.15 (JNS) Koyo + Emerson; JNS differs in r min NK5/12TN 5 10 12 0.2 (Koyo) / 0.15 (JNS) Koyo + Emerson; JNS differs in r min NK6/10 6 12 10 0.2 (Koyo) / 0.15 (JNS) Koyo + Emerson; JNS differs in r min NK6/12TN 6 12 12 0.2 (Koyo) / 0.15 (JNS) Koyo + Emerson; JNS differs in r min NK7/10TN 7 14 10 0.3 Koyo + Emerson NK7/12TN 7 14 12 0.3 Koyo + Emerson NK8/12 8 15 12 0.3 Koyo + Emerson NK8/16 8 15 16 0.3 Koyo + Emerson NK9/12 9 16 12 0.3 Koyo + Emerson NK9/16 9 16 16 0.3 Koyo + Emerson NK10/12 10 17 12 0.3 Koyo + Emerson NK10/16TN 10 17 16 0.3 Koyo + Emerson NK12/12A 12 19 12 0.3 Koyo + Emerson NK12/16 12 19 16 0.3 Koyo + Emerson RNA4900 14 22 13 0.3 Koyo + Emerson NK14/16A 14 22 16 0.3 Koyo + Emerson NK14/20A 14 22 20 0.3 Koyo + Emerson NK15/16A 15 23 16 0.3 Koyo + Emerson NK15/20A 15 23 20 0.3 Koyo + Emerson RNA4901 16 24 13 0.3 Koyo + Emerson NK16/16A 16 24 16 0.3 Koyo + Emerson NK16/20A 16 24 20 0.3 Koyo + Emerson RNA6901 16 24 22 0.3 Koyo NK17/16A 17 25 16 0.3 Koyo + Emerson NK17/20A 17 25 20 0.3 Koyo + Emerson NK18/16A 18 26 16 0.3 Koyo + Emerson NK18/20A 18 26 20 0.3 Koyo + Emerson NKS18A 18 30 16 0.3 Koyo NK19/16A 19 27 16 0.3 Koyo + Emerson NK19/20A 19 27 20 0.3 Koyo + Emerson RNA4902 20 28 13 0.3 Koyo + Emerson NK20/16A 20 28 16 0.3 Koyo NK20/20A 20 28 20 0.3 Koyo RNA6902A 20 28 23 0.3 Koyo NKS20A 20 32 20 0.6 Koyo NK21/16A 21 29 16 0.3 Koyo NK21/20A 21 29 20 0.3 Koyo RNA4903 22 30 13 0.3 Koyo + Emerson NK22/16A 22 30 16 0.3 Koyo NK22/20A 22 30 20 0.3 Koyo RNA6903A 22 30 23 0.3 Koyo NKS22A 22 35 20 0.6 Koyo NK24/16A 24 32 16 0.3 Koyo NK24/20A 24 32 20 0.3 Koyo NKS24A 24 37 20 0.6 Koyo NK25/16A 25 33 16 0.3 Koyo NK25/20A 25 33 20 0.3 Koyo RNA4904 25 37 17 0.3 Koyo + Emerson RNA6904A 25 37 30 0.3 Koyo NKS25A 25 38 20 0.6 Koyo NK26/16A 26 34 16 0.3 Koyo NK26/20A 26 34 20 0.3 Koyo NK28/20A 28 37 20 0.3 Koyo NK28/30A 28 37 30 0.3 Koyo RNA49/22 28 39 17 0.3 Koyo + Emerson RNA69/22A 28 39 30 0.3 Koyo NKS28A 28 42 20 0.6 Koyo NK29/20A 29 38 20 0.3 Koyo NK29/30A 29 38 30 0.3 Koyo NK30/20A 30 40 20 0.3 Koyo NK30/30A 30 40 30 0.3 Koyo RNA4905 30 42 17 0.3 Koyo + Emerson RNA6905A 30 42 30 0.3 Koyo NKS30A 30 45 22 0.6 Koyo NK32/20A 32 42 20 0.3 Koyo NK32/30A 32 42 30 0.3 Koyo RNA49/28 32 45 17 0.3 Koyo + Emerson RNA69/28A 32 45 30 0.3 Koyo NKS32A 32 47 22 0.6 Koyo NK35/20A 35 45 20 0.3 Koyo NK35/30A 35 45 30 0.3 Koyo RNA4906 35 47 18 (Koyo) / 17 (Emerson) 0.3 Koyo; Emerson differs in C RNA6906A 35 47 30 0.3 Koyo NKS35A 35 50 22 0.6 Koyo NK37/20A 37 47 20 0.3 Koyo NK37/30A 37 47 30 0.3 Koyo NKS37A 37 52 22 0.6 Koyo NK38/20A 38 48 20 0.3 Koyo NK38/30A 38 48 30 0.3 Koyo NK40/20A 40 50 20 0.3 Koyo NK40/30A 40 50 30 0.3 Koyo RNA49/32 40 52 20 0.6 Koyo + Emerson RNA69/32A 40 52 36 0.6 Koyo NKS40A 40 55 22 0.6 Koyo RNA4907 42 55 20 — Emerson (Fw, D, C only) RNA4908 48 62 22 — Emerson (Fw, D, C only) RNA4909 52 68 22 — Emerson (Fw, D, C only) RNA4910 58 72 22 — Emerson (Fw, D, C only) RNA4911 63 80 25 — Emerson (Fw, D, C only) RNA4912 68 85 25 — Emerson (Fw, D, C only) RNA4913 72 90 25 — Emerson (Fw, D, C only) RNA4914 80 100 30 — Emerson (Fw, D, C only) RNA4915 85 105 30 — Emerson (Fw, D, C only) RNA4916 90 110 30 — Emerson (Fw, D, C only) RNA4917 100 120 35 — Emerson (Fw, D, C only) RNA4918 105 125 35 — Emerson (Fw, D, C only) RNA4919 110 130 35 — Emerson (Fw, D, C only) RNA4920 115 140 40 — Emerson (Fw, D, C only) RNA4922 125 150 40 — Emerson (Fw, D, C only) Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - Koyo (JTEKT), via AIMS Industrial: Machined needle roller bearings without inner ring (catalogue pages 147 to 151): Fw, D, C, r min for NK, NKS, RNA49, RNA69 — web — Publisher's page; dimensions are facts — https://aimsindustrial.com.au/cdn/shop/files/Koyo-Machined-Needle-Roller-Bearings-without-Inner-Ring-Catalogue-Pages-147-to-151-Selected.pdf - Nose Seiko (JNS): Machined ring needle roller bearings without inner ring, NK / RNA catalogue pages 60 to 77 (Fw, D, C, rs min) — web — Publisher's page; dimensions are facts — https://www.albeco.com.pl/data/catalogueb/rna_nk_jns.pdf - Emerson Bearing: NK style standard needle roller bearings without inner ring: Fw, D, C — web — Publisher's page; dimensions are facts — https://products.emersonbearing.com/viewitems/standard-needle-roller-bearings/nk-style-standard-needle-roller-bearings?plpver=10 - Emerson Bearing: RNA 4900 standard needle roller bearings without inner ring: Fw, D, C — web — Publisher's page; dimensions are facts — https://products.emersonbearing.com/printitems/standard-needle-roller-bearings/rna-4900-standard-needle-roller-bearings?plpver=10 - McMaster-Carr: Needle bearings (free STEP/IGES per part, for your own design use; no redistribution) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution [verify license at link] — https://www.mcmaster.com/needle-bearings Free files (CC BY 4.0, Xem Studio; STEP + STL, 14 parts): https://xemstudio.com/files/hardware/needle-roller-bearings-nk-rna-nks/index.json API: https://xemstudio.com/api/geometry?object=needle-roller-bearings-nk-rna-nks