Klein Tools 631 Nut Driver Set, 7-Piece Hollow Shaft - Durable USA

In this review the Klein Tools 631 Tool Set is evaluated for electricians, maintenance techs, and serious DIYers who need a compact, reliable set of nut drivers. The biggest reason to buy is the combination of a practical size range and the 3-in hollow shaft design that allows work on long bolts while keeping a secure, twist-resistant blade anchor. The set's Cushion-Grip handles and Tip-Ident color coding make repeated use easier and faster, so the 631 performs like a small, focused kit worth keeping in a service bag.

Key Features

• Versatile size range: The seven hex sizes from 3/16 to 1/2 in cover the most commonly encountered nuts for electrical and general mechanical work.
• Hollow shaft design: The 3-in full hollow shafts permit use on long bolts while retaining clearance for internal flanges.
• Cushion-Grip handles: Soft but firm handles provide greater torque and comfort during extended tasks, reducing slippage.
• Tip-Ident color coding: Colored handle ends speed size identification and help avoid fumbling during fast-paced jobs.
• Made in USA construction: Domestic manufacture shows in solid feel and consistent workmanship for professional use.

Who It's For

The Klein 631 is aimed at professional electricians, field service technicians, and committed DIYers who need a compact, high-quality nut driver set that stays reliable under frequent use. Its hollow shafts and commonly used sizes make it particularly useful for tasks where access over long studs or bolts is necessary.

Those who primarily need precision miniature drivers or a very large architectural set with many specialty sizes should look elsewhere; this set is focused on practical, everyday hex sizes and durability rather than extreme specialty bits or extremely short drivers.

Pros & Cons

Pros

• Made in USA build quality that feels sturdy and durable in hand.
• Cushion-Grip handles deliver comfortable torque without slipping for repeated use.
• Tip-Ident color coding and a practical size selection speed up work.
• Hollow shaft design works on long bolts and internal-flange fasteners.

Cons

• Magnet strength on tips receives mixed feedback, varying by unit and task.
• Set includes only 3-in shafts; some users may want longer or shorter shafts for specific jobs.

Specifications

Brand	KLEIN TOOLS
Set contents	7 pieces: 3/16, 1/4, 5/16, 11/32, 3/8, 7/16, 1/2 in
Shaft length	3 in (76 mm)
Shaft type	Full hollow shaft with internal flanges
Handle	Cushion-Grip with Tip-Ident color coding
Country of origin	Made in USA

Our Verdict

The Klein Tools 631 is a compact, dependable nut driver set that delivers professional feel and practical utility for electricians and field technicians. With useful sizes, hollow shafts, and comfortable handles, it offers good value for anyone who needs a durable, no-nonsense driver set built to last.

Frequently Asked Questions

Are the shafts hollow?
Yes, the drivers use 3-in full hollow shafts with internal flanges to allow use over long bolts.

Do the handles help identify sizes quickly?
Yes, Tip-Ident color coding on the handle ends makes it easy to pick the correct hex size without reading small markings.

Is the set made domestically?
Yes, the set is made in the USA, reflecting Klein Tools' domestic manufacturing and quality control.