Dial-Able Header

Specs & Tech

Runout vs Tool life and tool Performance study was done at the BIG Daishowa Mega Technical Center in Awaji, Japan.

Figure 1: Here is a comparison of the effect of runout on tool life for three different 3-mm drills tested at four different runout values. The workpiece material was 1055 steel. The HSS tools were run at 90 sfm and the carbide tool was run at 250 sfm. Feed rate was 0.004 ipr.

The findings also show just how much significance a “small” amount of runout can have on a 3-mm drill. Runout of 0.0006 inch is close to the figure that shops considered good runout in the informal survey.

However, reducing the runout to well below this value improved the life of the carbide tool by almost 3 times. Even the least responsive tool saw tool life improvement of 60 percent.

Figure 2: Maximum Run-Out Based upon Tool Diameter & CLPT

Allowable TIR should be based on different values for tools of different diameters. Figure 2 shows the constant relationship between tool diameter and runout as a function of chip load.

The data is based on 0.0005 ” TIR as a starting point for a ½ “-dia. tool, from which the allowable TIR can be calculated for smaller tools and their respective chip loads.

Figure 3: Tool Life Efficiency vs. Run-Out

This study shows that as run-out increases tool life dramatically decreases. With the improvement of performance tooling it is more important than ever to reduce run-out for maximizing tool life and performance.