Rs40a
Router bit with an ARC stop ring, compatible with Zund cutting systems that run the RM-A QC ARC router and automatic bit changer. 1-flute upcut bit with a 0.039 in (1.0 mm) cutting diameter on a 0.236 in (6.0 mm) shank.
Sold individually.
Small detail for the ARC bit changer
The Rs40a puts a 0.039 in (1.0 mm) cutter on a 0.236 in (6.0 mm) shank with a stop ring, so the RM-A QC ARC automatic bit changer can load it at the same height every time. It cuts up to 0.157 in (4.0 mm) deep and is 2.283 in (58.0 mm) long overall.
What this bit is built for
A 0.039 in (1.0 mm) diameter cuts fine detail, small lettering, tight inside corners, and narrow slots that a larger bit cannot reach. With 0.157 in (4.0 mm) of cutting depth, it is made for thin sheet.
Single flute, upcut
One flute leaves the most room for chips to clear, which keeps heat down at the high speeds a small bit runs. The upcut direction pulls chips up and out of the cut, leaving a clean bottom edge.
Common questions
How do I know this fits my machine?
The Rs40a has a 0.236 in (6.0 mm) shank and a stop ring for the Zund RM-A QC ARC automatic bit changer. For a router without ARC that takes a 0.118 in (3.0 mm) shank, the Rs40 is the standard version. Not sure which you have? Send us your machine model and we will confirm before you order.
What speeds and feeds should I run?
The right spindle speed and feed rate depend on the material, its thickness, and your machine. Small bits break easily at high feed rates, so start slow. If you need help dialing in settings, contact us. We run these machines every day.
How do I know when to replace it?
Watch the edge finish and the chips. Rough or fuzzy edges, melting, or fine powder instead of clean chips all mean it is time for a fresh bit.
Getting the most from your cutting table
A fresh bit is a good start. But if you are going through bits faster than expected, or edge quality has become inconsistent, the bit is rarely the whole story. Spindle speed, feed rate, depth per pass, material hold-down, and machine condition all affect how long a bit lasts and how clean it cuts.
It is worth asking: When was your machine last serviced? Are your parameters dialed in for this material? Is this the right bit for what you are cutting? Could your operators use time with someone who runs these machines every day?
Flatbed Tools offers machine service, preventive maintenance, operator training, and workflow consulting. If something is not cutting right, reach out. We have probably seen it before.