Which sizes does this flex-head socket wrench feature?

This wrench combines two metric sizes: 12 mm on one end and 13 mm on the other.

How far do the wrench heads swivel?

Both socket heads swivel 180°, providing easier access to fasteners in confined spaces.

What is the benefit of the Dynamic-Drive profile?

The 12-point Dynamic-Drive profile applies torque to the fastener flanks, reducing wear and preventing fastener rounding.

What is the overall length of this wrench?

The overall length of this Bahco flex-head wrench is 224 mm.

BAHCO 4040M-12-13 knee spanner with Dynamic-Drive profile, chrome-plated, length 224 mm, 12 mm x 13 mm

Name: BAHCO 4040M-12-13 knee spanner with Dynamic-Drive profile, chrome-plated, length 224 mm, 12 mm x 13 mm
Brand: BAHCO
SKU: 41850587
Price: 28.8 EUR
Availability: PreOrder

Supplier number: BAHCO 4040M-12-13 | EAN 7314151078294

Recommended Retail Price €54.73

28.80 tax incl.

€23.80 excl. VAT (incl. all environmental contributions)

On order: delivered from 17/10/2026

Ordered before 20:00 - delivered as of 17/10/2026
Shipping costs €11.99 VAT included | Free shipping for orders over a total amount of 125 euros
Delivery by DHL
Lifetime warranty on Bahco? Or limited in time? Read more about it here.
Delivered from Belgium

✆ Talk to a specialist

Smooth fastener access around tight angles

Practical benefits

Flexible access in tight spaces: Both heads swivel 180°, allowing you to navigate around obstacles and reach deeply recessed nuts with ease.
Less wear on fasteners: The 12-point Dynamic-Drive profile distributes torque evenly across flat surfaces, preventing fastener damage and rounding during tough turns.
Rugged Bahco alloy construction: Engineered with high-performance alloy steel and a micro-matte chrome finish, it provides lasting protection against wear and corrosion.

In a nutshell

The right choise for

With the Bahco 4040m-12-13 flex-head socket wrench, you can easily access fasteners in confined spaces where standard ratchets or straight wrenches cannot reach. Both 12-point heads swivel 180°, allowing you to navigate smoothly around obstructions in tight engine bays and industrial machinery. The Dynamic-Drive profile applies torque directly to the fastener flanks, protecting your 12 mm and 13 mm nuts and bolts from wear and rounding. Made from high-performance alloy steel with a chrome-plated finish and an overall length of 224 mm, this dual-ended wrench gives you dependable leverage and lasting durability on tough maintenance jobs.

Product information FAQ

€28.80

tax incl.

Key features according to our expert

Width across flats 1: 12 mm
Width across flats 2: 13 mm
Key type: Socket wrench
Length: 223 mm

Product description:

Double ended flex-head wrenches with double hexagon sockets in metric sizes
Material: High performance alloy steel
Chrome plated Micro Matt finishing provides high quality surface
12 points Dynamic-Drive Profile provides longer life for screws and nuts
Both heads 180º swivelling. New design of the sockets for better accessibility
Retail packed on a plastic card

All Features

Width across flats 1: 12 mm
Width across flats 2: 13 mm
Key type: Socket wrench
Length: 223 mm
Width head 2 mm (d2): 17,8 mm
Width head 1 mm (d1): 16,6 mm
Length mm (l): 224 mm
Weight g: 160 g
Size mm: 12x13 mm

Brand BAHCO
41850587
EAN 7314151078294
Supplier number BAHCO 4040M-12-13
Warranty Lifetime warranty on Bahco? Or limited in time? Read more about it here.

Frequently asked questions about this product

Answered by specialists

Which sizes does this flex-head socket wrench feature?: This wrench combines two metric sizes: 12 mm on one end and 13 mm on the other.
How far do the wrench heads swivel?: Both socket heads swivel 180°, providing easier access to fasteners in confined spaces.
What is the benefit of the Dynamic-Drive profile?: The 12-point Dynamic-Drive profile applies torque to the fastener flanks, reducing wear and preventing fastener rounding.
What is the overall length of this wrench?: The overall length of this Bahco flex-head wrench is 224 mm.
What material is this wrench made from?: It is made from high-performance alloy steel with a chrome-plated finish.