Lathe Tool Holder

When a shortage of lathe tool holders was slowing down workflow on student projects, I looked into acquiring new tool holders. I realised very quickly that they were far more expensive than I could spare budget for and so I decided to make some new ones myself. I selected a free-cutting EN1A for ease of machining and took detailed measurements from one of the existing tool holders to enable the creation of a drawing. After a couple of successful tool holders had been made, I modified the design for a boring bar holder and made a couple of those too. I realised that the skills required made for an interesting student project and so I incorporated it into our EAL Diploma coursework and guided a class of students through the process of machining a tool holder. Students were successfully able to hold the +/- 0.1mm tolerance that I set for them and found the project more fulfilling and with more real-world utility than the suggested practice block originally set by the exam board.

The first student-completed lathe holder.

The first student-completed lathe holder.

This block is within a +/- 0.1mm tolerance.

This block is within a +/- 0.1mm tolerance.

There is nothing quite like a machined chamfer. Three meeting at a vertex like this looks very professional!

There is nothing quite like a machined chamfer. Three meeting at a vertex like this looks very professional!

The small relief step is noticeable in this shot. It's a small detail, but radically cuts down on friction while installing the tool.

The small relief step is noticeable in this shot. It's a small detail, but radically cuts down on friction while installing the tool.

This dovetail is quite tricky to measure, but after I made a go/no-go gauge, it became a lot easier!

This dovetail is quite tricky to measure, but after I made a go/no-go gauge, it became a lot easier!

A minor design change to the original design was required in order to hold this boring bar. I made a pair; one for each lathe.

A minor design change to the original design was required in order to hold this boring bar. I made a pair; one for each lathe.

The lay of the end mill is clearly visible in this image. Getting a really good surface finish on mild steel is fairly difficult, especially with a relatively light-weight milling machine.

The lay of the end mill is clearly visible in this image. Getting a really good surface finish on mild steel is fairly difficult, especially with a relatively light-weight milling machine.

I've been very happy with how these have worked. Insert tools are expensive, but make so much sense in a school workshop because anybody can keep them sharp, simply by replacing tips.

I've been very happy with how these have worked. Insert tools are expensive, but make so much sense in a school workshop because anybody can keep them sharp, simply by replacing tips.