Obviously the angles are different, a 118 degree bit has a sharper point which results in less walking and does not require a split tip like a 135 degree drill bit. 118 degrees makes a great hole and is considered by many to be a universal standard drill bit angle for the mass majority of your drilling needs.
For hard materials such as steel and stainless, 135-degree bits are best. The shallow angle allows the bit to cut into the material without dulling quickly, however that same shallow angle makes for a bit that wants to walk around, requiring a center punch.
Centerdrill countersink angles basically come in 3 angles: 60°, 82° and 90° included angles. A common angle used in live centers is 60°.
– Drill Point Angle: you can choose from many different drill point angles; two common types are 118°and 135°. The 118-degree drill is more suitable for mild steels, aluminium, and other soft metals. The 135-degree drill is more commonly used to drill hard steels, and other tough materials.
Drill Bits Angle
The standard angles of hss drill bits are 118, 120, 130, 135, 140, due to the processing materials are different, and the top drilling angle choosing is also different. For steel block through hole, it is usually uses 118 degrees. The cutting edge should not be too thin, too thin, and easy to wear.
Your two most common point angles will be 118 degrees and 135 degrees. A 118 drill bit is considered the universal standard for the majority of woods and soft metals. 135 degrees is a great point angle for drilling hard metals like steel.
For example, if you're drilling an 8 mm hole in brass you should set your drill to a speed of 2500 r.p.m. Or for stainless steel, which is much harder, the right drilling speed is 800 r.p.m. A good sign that you're using the right speed is that you'll get nice long shavings.
Carbide: The hardest and most brittle of the drill bit materials, it's used mostly for production drilling where a high-quality tool holder and equipment is used. It should not be used in hand drills or even drill presses. These bits are designed to drill into the hardest materials.
Titanium-coated HSS drill bits produce less friction. They're tougher than basic HSS bits and stay sharp longer. They work for drilling wood, metal, fiberglass and PVC. Carbide-tipped drill bits stay sharp much longer than steel, HSS or titanium bits.
Carbide is the strongest drill bit for metal and is typically reserved for professional-grade tools. Black Oxide is a coating added to HSS drill bits that helps reduce friction and speed up drilling through hard metals.
Drill at a Slow Speed
The faster a bit spins, the hotter it gets. And heat dulls bits quickly. In general, it's a good idea to drill through metal using as slow a speed as possible using a drill bit for metal. Hard metals like steel and larger drill bits require even slower speeds.
Pro Tip: Drilling into metal materials can add extra wear and tear on bits, even those designed for metal. Adding a lubricant such as WD-40® Multi-Use Product can reduce friction and allow for easier drilling and cutting into metallic parts.
What is the best drill bit for metal? Conventional drill bits cannot cut through metal so you need a heavy-duty, hard drill bit. Two types of drill bits are suitable for metalworking jobs: titanium and cobalt.
Each bit features a 135° split point tip design to help reduce walking.
High-quality drill bits aren't cheap. And once they become dull, they're ineffective and more likely to “walk” around and damage your workpiece. Luckily, a good drill bit sharpener can not only get them back in shape, but reinvigorate bits that snapped in half during aggressive use.
If you decide to sharpen by hand, you will need to use a vice to hold the bit steady, then file at a 60-degree angle. Run the file over the edges until they feel sharper. The simplest and most effective tool, however, is a bench grinder.
General-purpose drill points are often 118° angled drills, which are typically used for cutting into soft metals such as aluminum. The 135° variant of this drill bit is best suited for harder materials like stainless steel.
A drill bit has two cutting surfaces, one on each side of its center axis, that are cut at an angle of approximately 60 degrees.
You can easily drill an angled hole of up to 45 degrees. Between 45 degrees and 15 degrees, the process becomes more difficult, but not impossible. At lower than 15 degrees, the drill will move around too much. When the starter bit dances too much, you cannot establish a well-defined starter hole.
When drilling through hardened steel, you must ensure that your drill bit is made from tougher materials. Carbide bits are the strongest drill bits material and can cut through hardened steel. But if they are not available, titanium and cobalt drill bits can also be used.
If you're running the drill too fast, it may start making a chattering noise. This is caused by the drill bit deflecting and jumping around the hole as it's coming in contact with the part. Reducing speed will usually make the chattering go away. Sometimes you should use cutting fluid when drilling.