In pictures: How to keep your shear grab sharp

When it comes to winter feeding, most farms will have some form of attachment to feed animals such as shear grabs and bale slices.

The principle of these machines is the same – to cut through the material for feeding. In order to do their job efficiently, it is vital that they are kept sharp to reduce the time involved as well as the stress on other parts of the attachment. Dull blades will take longer to cut, and will not seal the face of the pit, leading to air getting in and spoiling the silage. They will also cause more strain to the hydraulics on the rest of the attachment, potentially leading to further problems such as structural cracks and bent or strained pins and hinge points.

In this piece, I am going to look at the best way to keep your shear grab sharp and working to its full potential.

What you need

This job requires very little time or tools. All you need is a second-cut flat file (medium grain file), heavy duty gloves to protect your hands from the sharp blade and eye protection along with a bit of good old elbow grease.

Step 1

Place the shear grab on the tractor and make sure all connections and locking pins are securely in place. Lower the grab on to level ground and open it fully. Apply the tractor’s handbrake and switch it off. Always remove the key when leaving the tractor to carry out any maintenance.

Step 2

Place an appropriate prop securely under the open grab and never stand or bend in under the blade, even when the prop is in place.

Step 3

Put on the heavy gloves and eye protection before commencing any work. Heavy gloves are crucial as they protect your hands from the sharpened blade. Place your flat file at a 45-degree angle on the chamfered face of the blade and draw file it in one direction only. Do not saw the blades; work from either the bottom to the top or vice versa, working from one side to the other, ensuring you cover all the blades evenly.

Step 4

When finished sharpening the blades, place the flat file under the cutting edge as shown and again draw file in one direction to remove any burr that may have formed. This will ensure the blade is as sharp as possible.

Never use an angle grinder to sharpen the blades. The heat generated from the spinning disc will remove the temper in the blade and destroy it, making it brittle and unable to hold an edge.

Dos

Don’ts

The principle with sharpening shear grabs is the same as bale shears and other such attachments.

So take three minutes no more than once a week looking after your blades edge as it will easily save you 30 minutes over the course of a few days as opposed to working with a blunt attachment, saving yourself some time and money this winter.