Knipex Collar cracker for aluminium collars (e.g. Hi-Lok), multi-component handles, 250mm, made in Germany 86 05 250 S5

The KNIPEX 86 05 250 S5 collar cracker is a specialised tool, purpose-built for safely forcing off aluminium break-away nuts (collars), commonly used on Hi-Lok® type fasteners widely found in aerospace manufacturing and precision fine-mechanics applications.
Unlike a standard adjustable plier, this model is built for a single mission, which it performs flawlessly: releasing the collar quickly and under control, without damaging surrounding parts and without the risk of the joint slipping during work.

Adjustment is fast, done by simply pressing the button directly on the workpiece, and the 19 adjustment positions allow instant adaptation to different collar sizes. Pressing strength is increased tenfold relative to the manual force applied, meaning control and efficiency even in the tight workspaces typical of aircraft maintenance or precision industrial equipment.

The box-joint design keeps play to a minimum and delivers consistent force transmission throughout the tool's service life, even after a high number of intensive-use cycles. Combined with the parallel-guided gripping jaw, it removes the risk of slipping on the workpiece surface and protects the collar from damage while it is being released.

The tool body is forged from high-performance chrome vanadium steel, oil-hardened for toughness and wear resistance, while the multi-component handles provide a secure, comfortable grip even during extended use or while wearing protective gloves. Made entirely in Germany, the KNIPEX 86 05 250 S5 meets the brand's strict quality standards, making it a reliable investment for technicians, fitters and specialists in aerospace or industrial maintenance.
The tool is also available in a compact 180mm version (KNIPEX 86 05 180 S5), so workshops regularly handling Hi-Lok® collars of varying sizes can cover the full range of applications with both lengths in the 86 05 family, while keeping the same operating principle and build quality.

Important note: this tool is intended exclusively for aluminium collars; it is not suitable for steel or titanium collars.

Quality down to the smallest detail

Sometimes we're really tough on our pliers. We try to break them, just to find out what makes them good and long-lasting. Because we don't want to leave anything to chance, we take a long, close look at every detail.
The steel used by KNIPEX is precision-hardened, with defined chrome and vanadium content, guaranteeing top performance and a long service life — even though this requires special production and costs a little more. But our high product standards demand it.
Every angle, every edge radius, the hardness and sharpness of the cutting edges, the precision and smoothness of the joint, the handle shape and the finish are constantly reviewed, tested and improved — so the tool you hold today still performs the same way after a decade of intensive use.
This special tool is built for one job, and it does it perfectly: safely releasing aluminium collars without damaging surrounding parts or slipping on the workpiece.

Package contents

• 1 x Collar cracker for aluminium collars (e.g. Hi-Lok®), multi-component handles, 250mm, KNIPEX 86 05 250 S5

Technical specifications

 

Spec	Value
Manufacturer code	86 05 250 S5
Material	Chrome vanadium electric steel, forged, oil-hardened
Finish	Chrome-plated / zinc-plated
Handles	Multi-component
Total length	266 mm
Dimensions	266 x 57 x 18 mm
Weight	515 g
Adjustment positions	19
Jaw thickness (joint) T1	8 mm
Joint thickness B3	14 mm
Country of origin	Germany
REACH compliant	Does not contain SVHC

KNIPEX 86 05 250 S5 is a special collar cracker pliers, used to force off aluminium break-away nuts (collars), for example on Hi-Lok® screw fasteners. It is not suitable for steel or titanium collars. It has a length of 250mm (266mm overall), 19 adjustment positions, a box-joint design, multi-component handles, and is made from forged, oil-hardened chrome vanadium steel. The product is manufactured in Germany by KNIPEX and is recommended for aerospace maintenance, fine mechanics and precision industrial assembly.

Frequently Asked Questions (FAQ)

What is the KNIPEX 86 05 250 S5 used for?
It is used to loosen aluminum locknuts (clamps), for example on Hi-Lok® screws, which are frequently used in the aerospace industry and precision mechanics.

Can it be used on steel or titanium clamps?
No. These pliers are intended exclusively for aluminum clamps; they are not suitable for steel or titanium clamps.

How many adjustment positions does it have?
It has 19 adjustment positions, for quick adaptation to different clamp sizes, plus quick adjustment by pressing the button directly on the workpiece.

Is it also available in other lengths?
Yes. The series also includes a compact 180mm version (KNIPEX 86 05 180 S5), to cover a full range of sizes.