# Proto

**Manufacturer:** Proto  
**MPN:** `J4990R-8M`

## Specifications

| Attribute | Value |
| --- | --- |
| Brand name | Proto |
| Manufacturer name | Proto |
| Manufacturer | Proto |
| DimensionUnit | inch |
| GraingerSku | 56JT03 |
| Extra Product Name | Proto |
| UPC | 662679185800 |
| UnitOfMeasure | EA |
| Weight | 0.15 |
| WeightUnit | lbs |
| atoms | 8 |
| cali_prop65_orglabel | False |
| cali_prop65_whtlabel | False |
| countryOfOrigin | TW |
| height | 0.8 |
| jsonUrlData | 924526ffbdad25e5923b |
| length | 3 |
| moq | 1 |
| MPN | J4990R-8M |
| multiple | 1 |
| qtyInStock | 30 |
| qtyInStockOverride | -2 |
| SKU | G4388188 |
| tierMinQty1 | 1 |
| tierPrice1 | 10.34 |
| url | https://www.zoro.com/proto-8-mm-tip-socket-bit-metric-38-in-drive-j4990r-8m/i/G4388188/ |
| width | 1.2 |
| Drive Size | 3/8 in |
| SAE or Metric | Metric |
| Number of Points | 6 |
| Measurement Type | Metric |
| Overall Length | 2 3/4 in |
| Material | Alloy Steel |
| Item | Socket Bit |
| Finish | Chrome |
| Tip Size | 8 mm |
| Standards | ANSI |
| Insert Length | Not Found |
| Features | Anti-Slip, Bi-Directional, To Help Prevent Compromised Fasteners, To Withstand the High Torque and Force Associated with Impact Tools in Repetitive Application, Side Locking Hole |
| Impact Rated | No |
| Bit Style | Hex |
| Replaceable Insert | No |
| Non-Sparking | No |
| Tip Style | Hex |
| Insulated | No |
| Country of Origin (subject to change) | Taiwan, Province of China |

## Distributor availability

| Distributor | SKU | Price (USD) | Qty | Stock | MOQ |
| --- | --- | --- | --- | --- | --- |
| Zoro | G4388188 | 10.34 | 1 | 30 | 1 |
| grainger.ca | PRT4990R8M | 16.2943447 | 1 | None | 1 |
| Grainger | 56JT03 | 15.57 | 1 | None | 1 |

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Structured data: `/python/html6/product/500/199000000/199384000/part_--J4990R8M---Proto--15ebd99e2a.json`  
Search API: https://www.dataalchemy.com/api/  
MCP server: https://www.dataalchemy.com/mcp