Luger Frame Tooling Marks Study

[CJS57]

Can anyone explain how Erfurt machined the blind ended square cutout shown in the very first post? The DWM circular end mill process is obvious. But for square corners like Erfurt, a square broach usually needs to go completely through the workpiece?

[DonVoigt]

Originally Posted by CJS57

Can anyone explain how Erfurt machined the blind ended square cutout shown in the very first post? The DWM circular end mill process is obvious. But for square corners like Erfurt, a square broach usually needs to go completely through the workpiece?

Likely used a key-way cutter , horizontally from the top inside;
sure what the marks look like.

[sheepherder]

Originally Posted by CJS57

Can anyone explain how Erfurt machined the blind ended square cutout shown in the very first post?

Can you link the post? Or post a new pic with the area outlined?

Some tools used at the turn of the century no longer exist, except in the memories of old workers.

[Ron Wood]

Originally Posted by CJS57

Can anyone explain how Erfurt machined the blind ended square cutout shown in the very first post? The DWM circular end mill process is obvious. But for square corners like Erfurt, a square broach usually needs to go completely through the workpiece?

The apparent square cutout is an illusion caused by the lighting. The square end of the cut actually stands proud of (above) the milled out area behind it.