Annular cutters for metal drilling: HSS and TCT

When it comes to industrial drilling, precision, efficiency, and tool durability are the key. Annular cutters, also known as core drills, tube drills, or hollow drills offer numerous advantages for professionals working on diverse materials, including steel and other tough metals.

As they allow for drilling holes in solid material without the need for pre-drilling, annular cutters are a highly effective alternative to traditional twist drills. Let us explore the features and benefits of using annular cutters.

Metric Annular Cutters: HSS and TCT

Available in metric sizes, these cutters come in two main types: HSS (High-Speed Steel) and TCT (Tungsten Carbide-Tipped).

HSS cutters are made of high speed steel with multi-cut geometry designed for ply-cutting, which improves chip removal. Their cutting edges can be resharpened, extending the lifespan of the tool and reducing replacement costs.

TCT cutters incorporate selected special-purpose carbide tips with multi-cut geometry for ply-cutting, lower friction, and reduced damage of tips. Like HSS cutters, they feature multi-cut geometry for enhanced cutting precision and efficiency. TCT cutters are known for their durability, especially when drilling harder materials.

PROMOTECH HSS high-speed steel cutters are available in two cutting lengths, 1″ and 2″, ranging from ø 12 mm to ø 50 mm. 3″ and 4″ are available on request.

For diameters over ø 50 mm, we offer TCT (Tungsten Carbide-Tipped) cutters with carbide-tipped teeth. TCT cutter 200mm that is used in PRO-200 ATEX drilling machine is available on request. Cutting length refers to the maximum material thickness that can be drilled through. We also offer TCT cutters designed for rail drilling, ø up to 36mm.

Both types of annular cutters use Weldon shanks, providing firm clamping for stable cutting and precise hole finishing. For HSS cutters up to 65mm or TCT up to 60mm, a Weldon 19mm (3/4”) shank provides the necessary fit. Whereas for cutters larger than 65mm – Weldon 31.75 (1 1/4”) shank is recommended.

Why Do Annular Cutters Outperform Traditional Twist Drills?

As annular cutters do not require a guide, they can drill open holes or overlapping holes (similar to slot-shaped holes). Such cylinder “slug”, received after cutting the hole with core drill, can be used as valuable material. This is especially important when drilling large-diameter holes in expensive, thick materials. Twist drills, on the other hand, shatter the entire hole into chips.

Cut Down Time and Costs

Producing burr-free holes, annular cutters eliminate the need for pilot holes and step drilling, significantly reducing time and cost of extra processing.

By cutting only the periphery of the hole, they also require only 30% power of what a twist drill would need. Using an annular cutter on a drill with a power output of around 1600W expands its drilling capacity from a maximum ø 32 mm (using a twist drill) to ø100mm (i.e. in upcoming PRO-102 drilling machine). At the same time, drilling efficiency increases significantly. For example, a hole with a ø 25 mm diameter in a 25 mm thick steel plate can be drilled with an annular cutter in just 25 seconds.

HSS core drills can be re-sharpened i.e. with annular cutter regrinding machine SM-101. It saves time and money, particularly if the customer is in urgent need for continued production drilling. Thanks to its solid construction, low power consumption, small dimensions, the machine can be used in any place.

SM-101 is designed for maximum ease of use, offering a quick and simple setup and quick positioning of the cutting tool. The adjustable angle feature allows for precise alignment with the original geometry. Equipped with a diamond wheel, it delivers sharp, clean cutting edges, while the laser-guided alignment guarantees perfect positioning of the cutter to the wheel for optimal performance.

Versatile and Efficient Solution

Because they require less cutting force, annular cutters allow for the use of smaller, more portable machines without sacrificing cutting capacity. What is more, annular cutters can drill on curved surfaces such as pipes and tubing, and can even create overlapping or open-edge holes, allowing for a broader range of applications.

This way, PROMOTECH’s annular cutters can be used and deliver exceptional performance across a wide range of stationary machines, including drills, lathes, and milling machines, both in mechanically controlled and CNC versions.

Check PROMOTECH’s drilling machines >>

Annular Cutters in Industrial Applications

Annular cutters are commonly used in a variety of industries where precision drilling through steel, aluminium, or other metals is essential. These industries include:

  • Manufacturing: In the production of machinery, automotive parts, and heavy equipment.
  • Construction: In structural steel fabrication to drill precise holes in beams, columns, and other metal components for bolting and assembly.
  • Oil & Gas Industry: pipelines, storage tanks, and metal structures during maintenance and installation work.
  • Shipbuilding: metal ship components, whether for structural fabrication, repair, or modifications in marine environments.
  • Railway: in rail tracks, metal plates, and other components for maintenance and construction of railway systems. For this purpose, check PRO-36R, available in petrol, electric, and CAS battery powered versions.
  • Automotive: In the automotive industry, annular cutters are used for drilling holes in car frames, parts, and equipment during assembly or customization.
  • Metal Fabrication: in sheet metal, pipes, and other metal components for various fabrication projects.
  • Infrastructure & Utilities: in the installation and maintenance of infrastructure, including drilling into metal supports, brackets, and structures for bridges, towers, and utility poles.

By removing only the material at the periphery of the hole, annular cutters drill holes up to three times faster than traditional twist drills. This efficient process significantly reduces the volume of material being cut and produces far fewer chips, making them the preferred choice in industrial and metalworking settings where speed and precision are critical.