# Spur gears, 48 diametral pitch (DP): 12 to 60 teeth, 14.5° and 20° involute, pitch / outside / root diameter and STEP/STL

> What is the pitch diameter, outside diameter and root diameter of a 48 DP spur gear, and how many teeth does it have?

- Category: Hardware › Bearings, rails & motion
- Kind: Hardware
- Basis: AGMA / ANSI diametral-pitch relations: pitch Ø = N / DP, outside Ø = (N + 2) / DP, minimum dedendum per ANSI B6.1 (20° coarse), Machinery's Handbook (14.5°) and ANSI B6.7 (20 DP and finer); true involute flanks generated point by point
- Page: https://xemstudio.com/objects/spur-gears-dp-48/ · JSON: https://xemstudio.com/api/geometry?object=spur-gears-dp-48 · Plain text: https://xemstudio.com/objects/spur-gears-dp-48/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**Exact dimensions.** Every file is drawn at true size with no tolerance added. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your process's clearance before making the part.

## Notes

- 48 diametral pitch (DP) means 48 teeth per inch of pitch diameter: pitch diameter = N / 48 in, outside diameter = (N + 2) / 48 in, circular pitch = π / 48 = 0.0654 in (1.662 mm), addendum 1 / 48 = 0.0208 in (0.529 mm), tooth thickness on the pitch circle π / (2 × 48) = 0.0327 in. Centre distance of two gears = (N1 + N2) / (2 × 48) in = 0.265 (N1 + N2) mm. Module equivalent: 0.5292. A 48 DP gear does not mesh with a metric module gear unless the two are within rounding of each other; use the module pages for metric gears.
- 20 DP and finer is fine-pitch (ANSI B6.7): whole depth 2.2 / P + 0.002 in and dedendum 1.2 / P + 0.002 in for both 14.5° and 20° (minimum values), so both pressure angles share one root diameter here. The table lists root and base diameters for both pressure angles so a hob or a CAD mate can be checked. 14.5° and 20° gears do not mesh: the pair must have the same DP and the same pressure angle. 14.5° is the older Brown & Sharpe / Boston Gear stock form (undercut below 32 teeth), 20° the current standard (undercut below 18 teeth).
- Files: 26 gears, a 14.5° and a 20° gear for each of the 13 tooth counts, as one extruded solid with a plain bore. Flanks are the true involute of the base circle, tooth thickness on the pitch circle half the circular pitch (no backlash), outside and root diameters as in the table, the root circle held at the root diameter for every tooth count (the flank is carried down to it; the real root fillet and trochoid are not modelled). Example choices (not published values): face width 3/16 in (4.76 mm), which is 8 / DP rounded to 1/16 in, and a bore of about a third of the root diameter picked from 1/16, 1/8, 3/16, 1/4, 5/16, 3/8, 1/2, 5/8, 3/4, 1 in. Hubs, keyways and set-screw holes are not drawn. Teeth below 32 (14.5°) and 18 (20°) are drawn without profile shift, so they are undercut-prone as real unshifted gears are.
- Stock tooth counts: the 12 to 60 range covers common stock gears (Boston Gear lists 16 DP 14.5° 14-tooth with 0.875 in pitch diameter, 1 in outside diameter, 0.5 in face, 0.375 in bore, which the formulas above reproduce; SDP/SI lists 48 DP gears from 14 to 108 teeth). Face widths and bores of stock gears vary by maker and series; those are not a standard.
- Left out: the 25° pressure angle, stub and profile-shifted teeth, tolerances (AGMA quality numbers), backlash allowances, helical and bevel forms, and hub dimensions. Maker CAD: SDP/SI publishes inch-pitch spur gears with per-part CAD; linked, not copied.

## Mating features (exact size; open press / slide / run / socket by your process clearance, leave designed and clamp as drawn)

| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| bore | plain bore, example Ø per file (1/16 to 1 in, see the table) | shaft of the same Ø | slide | gear-* |
| centre distance | (N1 + N2) / (2 × 48) in = 0.2646 (N1 + N2) mm | a second 48 DP gear of the same pressure angle (this family) | designed | gear-* |
| tooth form | 48 DP, 14.5° or 20° (the file name carries the angle); 14.5° and 20° gears do not mesh | 48 DP gear of the same pressure angle | designed | gear-* |

## Sizes

| teeth N | pitch Ø = N / DP, in (mm) | outside Ø = (N + 2) / DP, in (mm) | root Ø 14.5°, in (mm) | root Ø 20°, in (mm) | base Ø 14.5°, in (mm) | base Ø 20°, in (mm) | example face, in | example bore, in |
|---|---|---|---|---|---|---|---|---|
| 12 | 0.25 (6.35) | 0.2917 (7.41) | 0.196 (4.98) | 0.196 (4.98) | 0.242 (6.15) | 0.2349 (5.97) | 3/16 | 1/16 |
| 14 | 0.2917 (7.41) | 0.3333 (8.47) | 0.2377 (6.04) | 0.2377 (6.04) | 0.2824 (7.17) | 0.2741 (6.96) | 3/16 | 1/16 |
| 16 | 0.3333 (8.47) | 0.375 (9.52) | 0.2793 (7.10) | 0.2793 (7.10) | 0.3227 (8.20) | 0.3132 (7.96) | 3/16 | 1/16 |
| 18 | 0.375 (9.52) | 0.4167 (10.58) | 0.321 (8.15) | 0.321 (8.15) | 0.3631 (9.22) | 0.3524 (8.95) | 3/16 | 1/16 |
| 20 | 0.4167 (10.58) | 0.4583 (11.64) | 0.3627 (9.21) | 0.3627 (9.21) | 0.4034 (10.25) | 0.3915 (9.95) | 3/16 | 1/8 |
| 24 | 0.5 (12.70) | 0.5417 (13.76) | 0.446 (11.33) | 0.446 (11.33) | 0.4841 (12.30) | 0.4698 (11.93) | 3/16 | 1/8 |
| 28 | 0.5833 (14.82) | 0.625 (15.88) | 0.5293 (13.45) | 0.5293 (13.45) | 0.5648 (14.34) | 0.5482 (13.92) | 3/16 | 1/8 |
| 30 | 0.625 (15.88) | 0.6667 (16.93) | 0.571 (14.50) | 0.571 (14.50) | 0.6051 (15.37) | 0.5873 (14.92) | 3/16 | 3/16 |
| 32 | 0.6667 (16.93) | 0.7083 (17.99) | 0.6127 (15.56) | 0.6127 (15.56) | 0.6454 (16.39) | 0.6265 (15.91) | 3/16 | 3/16 |
| 36 | 0.75 (19.05) | 0.7917 (20.11) | 0.696 (17.68) | 0.696 (17.68) | 0.7261 (18.44) | 0.7048 (17.90) | 3/16 | 3/16 |
| 40 | 0.8333 (21.17) | 0.875 (22.22) | 0.7793 (19.80) | 0.7793 (19.80) | 0.8068 (20.49) | 0.7831 (19.89) | 3/16 | 1/4 |
| 48 | 1 (25.40) | 1.0417 (26.46) | 0.946 (24.03) | 0.946 (24.03) | 0.9681 (24.59) | 0.9397 (23.87) | 3/16 | 5/16 |
| 60 | 1.25 (31.75) | 1.2917 (32.81) | 1.196 (30.38) | 1.196 (30.38) | 1.2102 (30.74) | 1.1746 (29.84) | 3/16 | 3/8 |

## Where the files are

- Martin Sprocket & Gear: [G-85 spur gear data: PD = N / DP, OD = (N + 2) / DP, a = 1 / DP, ht = 2.157 / DP, t = 1.5708 / DP](https://martinsprocket.com/docs//partinterchange/g-85.pdf) — web — Publisher's page; dimensions are facts
- Engineers Edge: [Gear design equations: 20 degree full-depth teeth (ANSI B6.1): PD, OD, a = 1/P, b = 1.25/P, ht = 2.25/P, centre distance](https://engineersedge.com/gear_formula.htm) — web — Publisher's page; dimensions are facts
- Machinery's Handbook, 31st ed. (online edition): [Spur gearing: 14.5 degree full-depth tooth proportions (a = 1/P, b = 1.157/P, ht = 2.157/P)](https://online.flippingbook.com/view/954046886/872) — web — Publisher's page; dimensions are facts
- Machinery's Handbook, 31st ed. (online edition): [Table 4: tooth proportions for fine-pitch involute spur and helical gears of 14.5, 20 and 25 degrees (ANSI B6.7): b = 1.2/P + 0.002, ht = 2.2/P + 0.002](https://online.flippingbook.com/view/954046886/870) — web — Publisher's page; dimensions are facts
- Machinery's Handbook, 31st ed. (online edition): [Spur gearing: outside and root diameter formulas, 20 degree fine-pitch full-depth teeth (20 P and finer)](https://online.flippingbook.com/view/954046886/873) — web — Publisher's page; dimensions are facts
- Applied Industrial (Boston Gear): [Boston Gear 16 DP 14.5 degree 14-tooth steel spur gear: PD 0.875 in, OD 1 in, face 0.5 in, bore 0.375 in](https://www.applied.com/c-brands/c-regal-rexnord/c-boston-gear/nb14b-3-8/16-DP-14-5-PA-14-Teeths-Steel-Spur-Gear/p/101752354) — web — Publisher's page; dimensions are facts
- SDP/SI: [48 DP inch spur gears (catalogue pages list the tooth counts and bores; CAD per part on each product page)](https://shop.sdp-si.com/s1084z-048a040.html) — web — Publisher's page; dimensions are facts
- SDP/SI: [Inch pitch spur gear catalogue sheet](https://shop.sdp-si.com/media/pdf/81001085.pdf) — web — Publisher's page; dimensions are facts

## Free STEP/STL (26 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/spur-gears-dp-48/index.json

- gear-dp48-14-5pa-12t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-12t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-12t.stl) — 48 DP spur gear, 12 teeth, 14.5° pressure angle: pitch Ø6.350 mm (0.25 in), outside Ø7.408 mm (0.2917 in), root Ø4.978 mm; face 4.76 mm (3/16 in) and bore Ø1.587 mm (1/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-20pa-12t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-12t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-12t.stl) — 48 DP spur gear, 12 teeth, 20° pressure angle: pitch Ø6.350 mm (0.25 in), outside Ø7.408 mm (0.2917 in), root Ø4.978 mm; face 4.76 mm (3/16 in) and bore Ø1.587 mm (1/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-14-5pa-14t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-14t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-14t.stl) — 48 DP spur gear, 14 teeth, 14.5° pressure angle: pitch Ø7.408 mm (0.2917 in), outside Ø8.467 mm (0.3333 in), root Ø6.037 mm; face 4.76 mm (3/16 in) and bore Ø1.587 mm (1/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-20pa-14t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-14t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-14t.stl) — 48 DP spur gear, 14 teeth, 20° pressure angle: pitch Ø7.408 mm (0.2917 in), outside Ø8.467 mm (0.3333 in), root Ø6.037 mm; face 4.76 mm (3/16 in) and bore Ø1.587 mm (1/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-14-5pa-16t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-16t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-16t.stl) — 48 DP spur gear, 16 teeth, 14.5° pressure angle: pitch Ø8.467 mm (0.3333 in), outside Ø9.525 mm (0.375 in), root Ø7.095 mm; face 4.76 mm (3/16 in) and bore Ø1.587 mm (1/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-20pa-16t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-16t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-16t.stl) — 48 DP spur gear, 16 teeth, 20° pressure angle: pitch Ø8.467 mm (0.3333 in), outside Ø9.525 mm (0.375 in), root Ø7.095 mm; face 4.76 mm (3/16 in) and bore Ø1.587 mm (1/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-14-5pa-18t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-18t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-18t.stl) — 48 DP spur gear, 18 teeth, 14.5° pressure angle: pitch Ø9.525 mm (0.375 in), outside Ø10.583 mm (0.4167 in), root Ø8.153 mm; face 4.76 mm (3/16 in) and bore Ø1.587 mm (1/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-20pa-18t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-18t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-18t.stl) — 48 DP spur gear, 18 teeth, 20° pressure angle: pitch Ø9.525 mm (0.375 in), outside Ø10.583 mm (0.4167 in), root Ø8.153 mm; face 4.76 mm (3/16 in) and bore Ø1.587 mm (1/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-14-5pa-20t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-20t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-20t.stl) — 48 DP spur gear, 20 teeth, 14.5° pressure angle: pitch Ø10.583 mm (0.4167 in), outside Ø11.642 mm (0.4583 in), root Ø9.212 mm; face 4.76 mm (3/16 in) and bore Ø3.175 mm (1/8 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-20pa-20t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-20t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-20t.stl) — 48 DP spur gear, 20 teeth, 20° pressure angle: pitch Ø10.583 mm (0.4167 in), outside Ø11.642 mm (0.4583 in), root Ø9.212 mm; face 4.76 mm (3/16 in) and bore Ø3.175 mm (1/8 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-14-5pa-24t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-24t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-24t.stl) — 48 DP spur gear, 24 teeth, 14.5° pressure angle: pitch Ø12.700 mm (0.5 in), outside Ø13.758 mm (0.5417 in), root Ø11.328 mm; face 4.76 mm (3/16 in) and bore Ø3.175 mm (1/8 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-20pa-24t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-24t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-24t.stl) — 48 DP spur gear, 24 teeth, 20° pressure angle: pitch Ø12.700 mm (0.5 in), outside Ø13.758 mm (0.5417 in), root Ø11.328 mm; face 4.76 mm (3/16 in) and bore Ø3.175 mm (1/8 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-14-5pa-28t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-28t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-28t.stl) — 48 DP spur gear, 28 teeth, 14.5° pressure angle: pitch Ø14.817 mm (0.5833 in), outside Ø15.875 mm (0.625 in), root Ø13.445 mm; face 4.76 mm (3/16 in) and bore Ø3.175 mm (1/8 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-20pa-28t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-28t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-28t.stl) — 48 DP spur gear, 28 teeth, 20° pressure angle: pitch Ø14.817 mm (0.5833 in), outside Ø15.875 mm (0.625 in), root Ø13.445 mm; face 4.76 mm (3/16 in) and bore Ø3.175 mm (1/8 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-14-5pa-30t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-30t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-30t.stl) — 48 DP spur gear, 30 teeth, 14.5° pressure angle: pitch Ø15.875 mm (0.625 in), outside Ø16.933 mm (0.6667 in), root Ø14.503 mm; face 4.76 mm (3/16 in) and bore Ø4.762 mm (3/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-20pa-30t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-30t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-30t.stl) — 48 DP spur gear, 30 teeth, 20° pressure angle: pitch Ø15.875 mm (0.625 in), outside Ø16.933 mm (0.6667 in), root Ø14.503 mm; face 4.76 mm (3/16 in) and bore Ø4.762 mm (3/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-14-5pa-32t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-32t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-32t.stl) — 48 DP spur gear, 32 teeth, 14.5° pressure angle: pitch Ø16.933 mm (0.6667 in), outside Ø17.992 mm (0.7083 in), root Ø15.562 mm; face 4.76 mm (3/16 in) and bore Ø4.762 mm (3/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-20pa-32t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-32t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-32t.stl) — 48 DP spur gear, 32 teeth, 20° pressure angle: pitch Ø16.933 mm (0.6667 in), outside Ø17.992 mm (0.7083 in), root Ø15.562 mm; face 4.76 mm (3/16 in) and bore Ø4.762 mm (3/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-14-5pa-36t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-36t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-36t.stl) — 48 DP spur gear, 36 teeth, 14.5° pressure angle: pitch Ø19.050 mm (0.75 in), outside Ø20.108 mm (0.7917 in), root Ø17.678 mm; face 4.76 mm (3/16 in) and bore Ø4.762 mm (3/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-20pa-36t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-36t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-36t.stl) — 48 DP spur gear, 36 teeth, 20° pressure angle: pitch Ø19.050 mm (0.75 in), outside Ø20.108 mm (0.7917 in), root Ø17.678 mm; face 4.76 mm (3/16 in) and bore Ø4.762 mm (3/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-14-5pa-40t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-40t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-40t.stl) — 48 DP spur gear, 40 teeth, 14.5° pressure angle: pitch Ø21.167 mm (0.8333 in), outside Ø22.225 mm (0.875 in), root Ø19.795 mm; face 4.76 mm (3/16 in) and bore Ø6.350 mm (1/4 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-20pa-40t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-40t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-40t.stl) — 48 DP spur gear, 40 teeth, 20° pressure angle: pitch Ø21.167 mm (0.8333 in), outside Ø22.225 mm (0.875 in), root Ø19.795 mm; face 4.76 mm (3/16 in) and bore Ø6.350 mm (1/4 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-14-5pa-48t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-48t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-48t.stl) — 48 DP spur gear, 48 teeth, 14.5° pressure angle: pitch Ø25.400 mm (1 in), outside Ø26.458 mm (1.0417 in), root Ø24.028 mm; face 4.76 mm (3/16 in) and bore Ø7.938 mm (5/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-20pa-48t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-48t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-48t.stl) — 48 DP spur gear, 48 teeth, 20° pressure angle: pitch Ø25.400 mm (1 in), outside Ø26.458 mm (1.0417 in), root Ø24.028 mm; face 4.76 mm (3/16 in) and bore Ø7.938 mm (5/16 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-14-5pa-60t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-60t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-14-5pa-60t.stl) — 48 DP spur gear, 60 teeth, 14.5° pressure angle: pitch Ø31.750 mm (1.25 in), outside Ø32.808 mm (1.2917 in), root Ø30.378 mm; face 4.76 mm (3/16 in) and bore Ø9.525 mm (3/8 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet
- gear-dp48-20pa-60t: [STEP](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-60t.step) · [STL](https://xemstudio.com/files/hardware/spur-gears-dp-48/gear-dp48-20pa-60t.stl) — 48 DP spur gear, 60 teeth, 20° pressure angle: pitch Ø31.750 mm (1.25 in), outside Ø32.808 mm (1.2917 in), root Ø30.378 mm; face 4.76 mm (3/16 in) and bore Ø9.525 mm (3/8 in) are examples, the tooth form is the standard's; true involute flanks, no hub, keyway, chamfer or root fillet

## Questions

**What is the pitch diameter of a 48 DP, 20 tooth gear?**

0.4167 in (10.583 mm); outside diameter 0.4583 in (11.642 mm).

**What is the tooth depth of a 48 DP gear?**

Whole depth 2.2 / 48 + 0.002 = 0.0478 in (minimum, ANSI B6.7 fine pitch).

**What is the centre distance of two 48 DP gears, 20 and 40 teeth?**

(20 + 40) / (2 × 48) = 0.6250 in (15.875 mm).

## Fits with

- [Spur gears, 12 diametral pitch (DP): 12 to 60 teeth, 14.5° and 20° involute, pitch / outside / root diameter and STEP/STL](https://xemstudio.com/objects/spur-gears-dp-12/)
- [Spur gears, 16 diametral pitch (DP): 12 to 60 teeth, 14.5° and 20° involute, pitch / outside / root diameter and STEP/STL](https://xemstudio.com/objects/spur-gears-dp-16/)
- [Spur gears, 20 diametral pitch (DP): 12 to 60 teeth, 14.5° and 20° involute, pitch / outside / root diameter and STEP/STL](https://xemstudio.com/objects/spur-gears-dp-20/)
- [Spur gears, module 1: 10 to 80 teeth (20° involute)](https://xemstudio.com/objects/spur-gears-module-1/)
- [Spur gears, involute 20°: module 0.5, 1 and 2, 12–60 teeth](https://xemstudio.com/objects/spur-gears-involute/)
- [Gear racks ISO 53 module 1 to 3: tooth profile, pitch, depth and root radius + module 1.5, 2.5, 3 rack STEP/STL](https://xemstudio.com/objects/gear-racks-iso-53-module-1-to-3/)