February 19, 2021 5 min read 0 Comments

There has been much debate from prominent respected shear sharpening educators about what is the best way to sharpen shears, either holding the shears in the hand or setting the shears in some sort of guided jig or clamp. There are good points on both sides of the debate. With experience in both methods, my preference is a guided system for many reasons.

Free hand sharpening can be quicker and more closely follows the edges made on shears in the factory. Using a guided shear sharpening system with a scissor flathone is easier to use when sharpening a variety of angles. A guided system gives a accurate edge with a lower learning curve. Using a jig or a clamp is easier to learn than free handing.

What is Free Hand Sharpening?

Free hand sharpening is sharpening done without use of a guided device to set the angle. Free handing is holding the shear (or knife) in your hand and guessing at the correct angle using hand positioning and visual clues to create a burr. In the case of free hand sharpening a beauty shear on a flathone machine, the handle of the shear is held in the hand. It is then held at a stationary position on a bevel edge to create a bur. On a convex edge beauty or groomer shear it is rotated from the face to the edge to create a clamshell shape and form a burr.

What is a Guided Shear Sharpening System or Shear Jig or Clamp?

A guided shear sharpening system has a jig or clamp that will hold the shears at a set angle so there is less guess picking an angle and a more consistent edge. Some of the jigs are merely stationary. Other shear clamps will rotate to the edge to create a convex edge. These devices must be able to hold the shears securely as well as attach to the flathone machine in an easy to maneuver fashion.

This video walks you through the reasons to use a clamp rather than free hand sharpening.



What Type of Sharpening is Used in the Factories?

Most factories in Asia use a free hand system. The free hand system is faster and a consistent repeatable edge can be achieved by those her have dexterity in their hands and are creating the same shear with the same factory edge angle over and over. When visiting factories in the USA and Germany I saw sharpening sometimes using a clamp and sometimes not. Free hand sharpening in the factory is less common in the USA and western countries. I was told by a shear factory owner from Korea that only those who grew up using chop sticks can successfully sharpen free hand. I don’t think this is necessarily true, but one needs to have good hand and eye coordination to sharpen free hand.

Which System a More  Accurate Edge?

Without a doubt, using a clamp or jig in a guided shear sharpening system like the one on the Scimech Flathone will produce an exact angle that can not be achieved in free hand sharpening. Setting the angle to the parameters of the shears, the customers and the intended use will assure the sharpener that the edge is correct in all respects.

What are the Common Angles Used on Shear Sharpening Jigs and Clamps

These are the most useful angles on shears and their general purposes.

Shear Purpose

USA Angles

Knife Angles & Asian Angles

Razor shears like the Fishbone



High end – slide cutting and point cutting

50 – 55


Normal Salon Use, Good Quality shears. Best for least push and good slicing



Heavy use, straight cutting



Most Barber Beveled Edges



Some thinners, groomers and barber shears



Sewing scissors, pinking shears, surgical scissors




What Types of Shear Sharpening Jigs and Clamps are on the Market?

Many companies make jigs and clamps for shears. Some of the guides are just that, they have a place to hold the shears up to a set angled space to keep the angle consistent, but do not have a clamping system to hold the shears. You would then need to hold the shears by hand next to the guide.

Two clamping systems for convex edge shears that work well are the one from Sharp Edges on the Hamurguri ™ and the jig used on the equipment by Wolff Industries, the Hira-to™.

The clamp I prefer is the Scimech Clamp. The one made for Bonika Shears, called the Scimech™ Flathone is one of the oldest and most trusted designs in the industry to create a convex edge. It has been in production since 1998. In 2003 the left hand version of the clamp was developed. Then in 2004 a single clamp designed for right and left handed shears was designed by Frank Davis. In 2018 the “HD” version of the clamp was designed with added features like the adjustable detant and the screw inset added.   

Other clamps and guides with corresponding flathone sharpening systems came on the market. Some clamp to set the 800 mm radius, which is a misnomer because shears can have a radius from 500 to 1200 and a clamp must be able to set all radii. Other clamps claimed to create a twist to the edge claiming that the angle changes as the burr travels down the edge. This is also an unnecessary feature as the angle is consistent throughout the length of the blade in shears that have been properly made in the factory. 

What Type of System is Best for the Hand?

Carpal tunnel and arthritis pain as well as back, shoulder and elbow paid can result from sharpening. It is important that you find a system that is comfortable for your body and hand. In practically every case, a jig or clamp is preferred over free hand sharpening for ergonomics. A clamp like the one on the Scimech allows the sharpener to either sit or stand when sharpening. In either position, the clamping system has less wrist twisting than most other systems allowing a person to sharpen shears into their 70’s, 80’s and even 90’s.

When Should Someone Free Hand Sharpen?

There are times when I free hand sharpening. Free hand sharpening is preferred for the following reasons:

  • Sharpening free hand is faster than putting shear in clamp. The polishing step alone done free hand can greatly reduce the time it takes to sharpen.
  • Curved Shears. Following the angle on curved shears can best be achieved with free-hand sharpening over most clamps. 
  • Left handed shears. If your jig or clamp is designed for right handed shears only, you may have to free hand sharpening all left handed shears.
  • Low quality shears. On sewing scissors, industrial shears, low quality barber shears, free hand sharpening which is faster can be sufficient. Repetitive sharpening of small scissors with blunt edges like manicure scissors, bandage and surgical scissors and embroidery scissors are often easier to sharpen free handed.