machine shop experts: drill bits???
what is the difference between the 135 degree drill bit, 118 degree drill bit, and the split point bits. I appreciate any advice or input you can contribute. thanx in advance.
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The 118 is the most common. It will walk very easy when trying to start a hole by hand. The 135 works better in harder material.
Split points are not supposed to walk when hand starting holes. They are best for wood.0 -
135 point angle is what we used in the shop for almost everything. I don't think the boss stocked the other angle bits. 118 are for wood, plastic, alum & soft steels.
We always back cut and split out bits if they weren't already that way when we got them.
We used an industrial Darex bit sharpener "V390"
http://www.darex.com/
Spliting helps it start straight, drill straight, & allows better chip removal.0 -
The most common angle is 118 degrees (each lip is 59 degrees from drill centerline) and for general use, this is what you'll usually get when buying drill bits. Greater angles stand up better on harder materials & smaller angles can be used on softer materials. The web is the center part inside the flutes & becomes thicker as drill is ground shorter. This increases pressure required to cut & thinning the web is beneficial. Best way is by grinding actual cutting edges (split points). 0 -
118 is the standard angle, 135 is used in bits like Cobalt for drilling harder steels. 0 -
quote:Originally posted by bambambam
135 point angle is what we used in the shop for almost everything. I don't think the boss stocked the other angle bits. 118 are for wood, plastic, alum & soft steels.
We always back cut and split out bits if they weren't already that way when we got them.
We used an industrial Darex bit sharpener "V390"
http://www.darex.com/
Spliting helps it start straight, drill straight, & allows better chip removal.
Negatory... We used standard 118's , thinned the webs to provide more chip clearance on exotic metals such as Inconel, hastings,hastalloy, 200/300 series stainless.0 -
quote:Originally posted by select-fire
quote:Originally posted by bambambam
135 point angle is what we used in the shop for almost everything. I don't think the boss stocked the other angle bits. 118 are for wood, plastic, alum & soft steels.
We always back cut and split out bits if they weren't already that way when we got them.
We used an industrial Darex bit sharpener "V390"
http://www.darex.com/
Spliting helps it start straight, drill straight, & allows better chip removal.
Negatory... We used standard 118's , thinned the webs to provide more chip clearance on exotic metals such as Inconel, hastings,hastalloy, 200/300 series stainless.
Boss bought them for A2,D2,S7, 4140HT& stainless....all tool steels.
We always use center bits to start a hole on tool steel or anything for that matter. If not you bit will wonder around until you get enough pressure to get a hole started.0 -
A split point drill bit has a "pilot point" or smaller diamter bit sticking out of the cutting end. It is used to start holes where pilot holes weren't used first. It's designed to keep the bit from walking when starting. 0 -
quote:Originally posted by Riomouse911
A split point drill bit has a "pilot point" or smaller diamter bit sticking out of the cutting end. It is used to start holes where pilot holes weren't used first. It's designed to keep the bit from walking when starting.
Has anyone tried a center drill bit?0 -
Has anyone tried a center drill bit?
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Use them on round stock especially, to start the hole and finish with the proper drill size. Also, used in the lathe to cut the hole for your center. Sizes vary according to the finished hole size.0
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