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Reasons your Crush Cut Holder Heats Up

A question we are asked frequently is, “should my crush cut holder heat up during operation?” even though the reason for heating up might vary, the bottom line should always be, “not really”. Due to the contact between two metal parts in motion, some friction and therefore heat is expected to be present in the knife holder, but this by no means should be scorching hot.

In this article, we will review some of the issues that may cause the holder to heat up, and how to address each issue to avoid this problem.

Common Reasons for Holders Heating Up:

1. Incorrect Knife Holder Mounting

One of the most common reasons why crush cut holders heat up has to do with how they are mounted onto the mounting surface. Due to the mechanics involved in crush cutting, the knife must always be completely perpendicular to the mounting surface to keep the forces acting up against the knife and the holder, in a single direction.

If a holder is incorrectly mounted, the forces acting up will be on 2 different directions, causing the blade to run up against the inside of the holder, wearing them both out, and heating up in the process.

Knife Misalignment: The Proper Knife Alignment

Therefore, if your crush cut holders are consistently heating up, you might want to take a look at the mounting procedure and make sure this is correct.

2. Incorrect Knife Sizes for the Holder being Used

Another very common mistake that causes crush cut holders to heat up is using an incorrect blade size for the holder that is in use. Dienes carries 3 different hub widths for the standard 3” crush cut blade. Depending on the type of holder, the size of the hub must be different.

Below we provide a table with 3 different widths Dienes offers, as well as an image showing what dimension this refers to, and the correct holder it should be used on:

Hub “S2” Width in Inches Hub “S2” Width in mm Type of Holder
0.244” 6.197 mm PQAS ½
0.25” 6.35 mm PQDS 12mm and 15 mm
0.2047” 5.2 mm PQDS 9mm, 10mm, 9.525mm and PQAS 3/8” holder



Measure the Correct Knife Size Guide

By using an incorrect knife size, it can cause the knife to jam (if it is too wide for the holder), or wiggle freely (if it is too thin). But, it both cases, the knife will be running against the inside of the holder causing it to wear and heat up.

If you are unsure about the size of your holder, simply measure its width looking at it from the front as shown in the diagram to the left. By measuring your holder width, it will give you your holder model.

3. Absence of Lubrication on the Knife Face

Another reason why a crush cut holder might heat up is due to a lack of lubrication. Between a small holder tolerance and the moving metal parts that are in contact with each other, it creates friction. As a result, some heat is produced.

However, without lubrication, the amount of generated heat from the moving parts may exceed what it should normally retain. Therefore, this accelerates the wear of the components and may cause heat to transfer from the knife onto the material.

A normal crush cut holder with proper lubrication may heat up to a range of 85°F-90°F. However, without lubrication, the holder may heat up to 115°F-125°F. As a result, this accelerates the wear of the bearings, knife and can wear a groove on the inside of the housing in a matter of hours, instead of months, as it should be. As a result, this makes the holder unfit for operation.  In conclusion, proper lubrication needs to be applied to the knife face to prevent excessive heat on the knife holder.

Other Negative Effects Due to Holder Heat Up:

Additionally, to the premature wear of both the holder and the knife due to the 2 of them being in contact, some additional problems can arise if this issue is not addressed. Some effects it may have on the holder include:

  1. Undesired heat treating to the blade, changing its properties.
  2. Increased scrap, due to the quality of the cut not being consistent.

Now you are aware of some of the reasons that may be causing your holder to heat up and how this should not be happening, and how to correct it. But, if you feel you need further assistance, do not hesitate to call our number today!

Reasons why your Crush Cut Holder Heats Up

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