# goBILDA 12 mm Thrust Ball Bearing (21 mm OD)

> goBILDA 1613-0521-0012 thrust ball bearing for 12 mm round shafting and 12 mm REX shafting: 12 mm bore, 21 mm outer diameter, 5 mm thick, bronze cage with high-carbon steel washers and balls, 6.0 g. Isolates axial load on large-shaft builds such as turntables and arms; no load ratings are published.

- Manufacturer: goBILDA
- Part number: 1613-0521-0012
- Category: Bearings
- Canonical page: https://www.xirkit.io/products/gobilda-12-mm-thrust-ball-bearing-21-mm-od-9f31
- Structured JSON: https://www.xirkit.io/products/gobilda-12-mm-thrust-ball-bearing-21-mm-od-9f31/data.json
- Source: Xirkit structured parts catalog — every value traced to a cited document; unknowns are explicit.

## Key specifications

| Property | Value |
| --- | --- |
| Bearing type | thrust ball |
| Bore (ID) | 12 mm |
| Outer diameter | 21 mm |
| Width | 5 mm |
| Material | Bronze Cage, High-Carbon Steel Washers and Balls |
| Weight | 6 g |
| Dimensions | 21 × 21 × 5 mm |

## Where to buy

| Supplier | Price | Stock | Checked | URL |
| --- | --- | --- | --- | --- |
| www.gobilda.com | 4.99 USD | in_stock | 2026-10-01 | https://www.gobilda.com/12mm-id-thrust-ball-bearing-12mm-id-x-21mm-od-5mm-thickness/ |

## FAQ

**How much does the goBILDA 12 mm Thrust Ball Bearing cost?**

From $4.99 at www.gobilda.com. Prices are observed unit prices before tax and shipping.

**What are the goBILDA 12 mm Thrust Ball Bearing dimensions?**

21 × 21 × 5 mm. A STEP model is available for enclosure fit checks.

**Where does this goBILDA 12 mm Thrust Ball Bearing data come from?**

Every value in this record is traced to a source — 2 documents including the board and chip datasheets — with the page and table cited per value. Unknowns are left explicit, never guessed.

## Sources

- [goBILDA 12 mm Thrust Ball Bearing (21 mm OD) datasheet](https://www.gobilda.com/12mm-id-thrust-ball-bearing-12mm-id-x-21mm-od-5mm-thickness/)
- [www.gobilda.com listing](https://www.gobilda.com/12mm-id-thrust-ball-bearing-12mm-id-x-21mm-od-5mm-thickness/)

## Part graph

### Alternatives (by use case)

- [goBILDA 6 mm Thrust Ball Bearing (14 mm OD)](https://www.xirkit.io/products/gobilda-6-mm-thrust-ball-bearing-14-mm-od-bb49) — Both serve robot joints and actuation — check the trade-offs; $3.99 vs $4.99
- [goBILDA 6×16×4 mm Ball Bearing (2-pack)](https://www.xirkit.io/products/gobilda-6-16-4-mm-ball-bearing-2-pack-1c27) — Both serve robot joints and actuation — check the trade-offs; $4.99 vs $3.99
- [goBILDA 12 mm Linear Ball Bearing 30 mm (2-pack)](https://www.xirkit.io/products/gobilda-12-mm-linear-ball-bearing-30-mm-2-pack-36ac) — Both serve linear motion and lifts — check the trade-offs; $4.99 vs $5.99
- [goBILDA 4×14×5 mm Flanged Ball Bearing (2-pack)](https://www.xirkit.io/products/gobilda-4-14-5-mm-flanged-ball-bearing-2-pack-3874) — Both serve robot joints and actuation — check the trade-offs; $4.99 vs $3.99
- [goBILDA 8 mm Thrust Ball Bearing (15.5 mm OD)](https://www.xirkit.io/products/gobilda-8-mm-thrust-ball-bearing-15-5-mm-od-425b) — Both serve robot joints and actuation — check the trade-offs; $4.99 vs $3.99
- [goBILDA 6 mm Linear Ball Bearing 35 mm (2-pack)](https://www.xirkit.io/products/gobilda-6-mm-linear-ball-bearing-35-mm-2-pack-a41d) — Both serve linear motion and lifts — check the trade-offs; $4.99 vs $6.99
- [goBILDA 5×14×5 mm Flanged Ball Bearing (2-pack)](https://www.xirkit.io/products/gobilda-5-14-5-mm-flanged-ball-bearing-2-pack-b645) — Both serve robot joints and actuation — check the trade-offs; $4.99 vs $3.99
- [goBILDA 8×22×7 mm Ball Bearing (2-pack)](https://www.xirkit.io/products/gobilda-8-22-7-mm-ball-bearing-2-pack-fd0e) — Both serve robot joints and actuation — check the trade-offs; $4.99 vs $3.99