You may have used a regular drill bit, but what about a split-point drill bit, and when should you use one?
A split-point drill bit also called a high-speed split-point drill bit, is a drill bit with a cutting angle of typically 135°, which is flatter than an ordinary drill bit (118°). It is so-called because of its grooved tip.
A split-point drill bit can center its speed and reduce the pressure required to drill. It is specially designed for drilling into hard surfaces such as metal without the risk of wandering. This is made possible by its two additional cutting edges and three grooves on its shaft to allow debris to come out easily. The ability to drill into tougher surfaces is due to the larger cutting angle than ordinary drill bits.
This guide will teach you how to identify a split point drill bit, know what features and uses they have, and understand their downsides and alternatives.
Identifying a Split Point Drill Bit
Identifying a split-point drill bit is not straightforward because they are not always labeled.
Like ordinary drill bits, they are also the twist-bit type of drill bits. To make it easy to identify one, here is a close-up of the tips of a split-point drill bit and an ordinary drill bit:
Notice the cut at the drill bit’s tip on the left and the flatter or rounder point. That’s a split-point drill bit. The one on the right has a smoother but sharper tip. That’s an ordinary or standard drill bit. The table below mentions some more differences to help you identify a split-point drill bit:
| A Split Point Drill Bit | An Ordinary Drill Bit | |
| Point/Tip | Flatter or rounder | Smoother and sharper |
| Point angle | 135° | 118° |
| Grooves/Spurs | Typically two | Typically three |
| Use a center punch first? | No need for that. | You may need to use it. |
| Best used for | Tougher materials (including tough steel) | Softer materials (no more than mild steel [1]) |
Split point drill bits are usually made of high carbon steel or a cobalt-steel alloy and are commonly available in sizes of 3/16” or 3/32”.
Special Features and Uses of Split Point Drill Bits
No Wandering
When you drill using ordinary drill bits, they tend to ‘wander’ due to their smooth tips, i.e., they don’t stay centered so easily.
Using a center punch before drilling with them can alleviate this problem, but a split-point drill bit may be a better choice. A split-point drill bit can be used to drill without needing a center punch. This makes them ideal for drilling into expensive hardwood if you are concerned about the marks or damage caused by wandering drill bits.
No Slipping
The grooved tip of a split-point drill bit gives it extra support to reduce the chances of the drill bit slipping. This makes them useful for drilling into slippery surfaces, such as metal pipes. The greater stability also makes them ideal to use in cordless drills.
Drill Into Tougher Surfaces with Greater Precision
The larger cutting angle of the split point drill bit enables it to drill into tougher surfaces such as metal, including copper, aluminum, and 10-18 steel. The holes made in tougher surfaces when using a split point drill bit tend to be a tighter fit than if using an ordinary drill bit.
Cleaner Holes
The shaft of a split point drill bit typically has three grooves. They help push the debris out of the hole, so you get cleaner holes. Using an ordinary drill bit, you have to blow out the debris yourself.
Quicker Drilling
The three grooves in a split-point drill bit give cleaner holes and allow you to drill holes faster. The grooves stretch to the tip making the split-point drill bit capable of anchoring into the wood more easily than an ordinary drill bit.
No Snagging
Split-point drill bits can also eliminate snags due to their finer holes.
Downsides and Alternatives
Downsides of Split Point Drill Bits
Despite several benefits, a downside to using split point drill bits is that they are not as sturdy as ordinary drill bits, i.e., they can be damaged more easily.
Also, you cannot sharpen them at all. If you try doing that, they will most likely break. If a split-point drill bit becomes dull, it is better to replace it simply. You can try grinding its tip if you still want to hold on to your split-point drill bit with a dull point.
Situations Where a Split Point Drill Bit Is Less Suitable
If you need to drill into a soft surface, such as softwood, aluminum, or plastic, it is better to use an ordinary drill bit instead. (1, 2, 3)
The smaller angle, chisel, and sharper tip are better alternatives for soft surfaces and materials. It’s not worth risking the more delicate split-point drill bit in these situations.
If You Can’t Find a Split-Point Drill Bit
If you want to use a split-point drill bit but can’t find one, you can use a screw point or spade-point drill bit instead. They have some similar qualities to split-point drill bits.
Wrapping Up
If you are going to drill into a hard surface, you want to avoid wandering and slipping, drill a cleaner and more precise hole, and avoid slag; use a split-point drill bit instead of an ordinary one. You can recognize a split point drill bit by its flatter tip.
Take a look at some of our related articles below.
References
(1) softwood – https://www.sciencedirect.com/topics/engineering/softwood
(2) aluminum – https://www.rsc.org/periodic-table/element/13/aluminium
(3) plastic – https://www.britannica.com/science/plastic