Klein Tools 646-5/16M Magnetic Nut Driver 5/16 Inch
- Head Style: Hex
- Material Type: Alloy Steel, Rubber
- Item Weight: 0.2 pounds
- Manufacturer Warranty Description: 1 year manufacturer
Last refreshed Aug 4, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A single-purpose 5/16 inch flat driver from Klein's well-rated line, useful mainly as a specific-size addition to a set rather than a starter tool.
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ASIN: B00093GECGModel: 646-5/16MCategory: Screwdrivers
Overview
Klein's 646-5/16M ships as one fixed-tip screwdriver, carrying a 5/16 inch flat blade. It measures 9.75 x 2 x 2 inches overall and weighs 0.2 pounds, with no handle material listed in the spec sheet.
Klein numbers its cabinet-tip drivers by size, and the 5/16M code is the clearest identifier of what this tool actually does since no handle material or shank type is listed. Buying it as a single piece makes sense for filling one gap in an existing set rather than starting a collection from scratch.
- 5/16 inch flat tip
- 9.75 x 2 x 2 inch overall size
- 0.2 pound weight
- Sold as a single piece
Who it's for
Electricians or technicians who need one specific 5/16 inch flat tip to fill a gap in an existing driver set. Not a fit for someone wanting a multi-bit or starter driver, since this ships as a single fixed tip.
Pros and cons
- Compact at 9.75 inches overall
- Light at 0.2 pounds for a pouch
- Sold individually to match one tip size
- Single fixed tip only
- No bit-swapping or storage case
- No handle material listed
Performance notes
Shank length of 9.75 inches gives enough reach into recessed screws, while the 2 x 2 inch handle footprint keeps grip diameter modest for a single-handed turn. Weighing 0.2 pounds, it adds little bulk to a tool pouch. Because the tip size is fixed at 5/16 inch, it is a one-job driver rather than a substitute for a multi-bit set.
Specifications
| Brand | KLEIN |
|---|---|
| Model | 646-5/16M |
| Dimensions & fit | |
| Item Weight | 0.2 poundslower than 70% of 112 screwdrivers |
| Item Dimensions | 9.7 × 2 × 2 inches |
| Head Size | 5/16 Inch |
| Construction & materials | |
| Material Type | Alloy Steel, Rubber |
| Color | Black |
| Included components | |
| Unit Count | 1 |
| Included Components | 5/16'' Magnetic Nut Driver 6" Cushioned |
| Warranty & support | |
| Manufacturer Warranty Description | 1 year manufacturer |
| Other details | |
| Head Style | Hex |
| Number Of Items | 1 |
| Recommended Uses For Product | Home Improvement, Auto Repair |
| Special Feature | Magnetic Tip |
| Item Type Name | Klein Tools 646-5/16M 5/16-Inch Hex Magnetic Tip Nut Driver With 6-Inch Hollow Shank |
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Frequently asked questions
What tip size does the Klein 646-5/16M use?
It carries a fixed 5/16 inch flat tip, as indicated by the model number.
Does the Klein 646-5/16M come with interchangeable bits?
No, it ships as a single fixed-tip screwdriver, one piece per package.
How much does the Klein 646-5/16M weigh?
It weighs 0.2 pounds and measures 9.75 x 2 x 2 inches overall.