ALPHA COUPE 7 Cobalt 5% Taps + 7 Gold&Black Drills Set

7-piece 5% Cobalt tap set + 7 Gold&Black ALPHA COUPE drill bits: precision and performance for hard steel

The 7-piece 5% Cobalt tap set + 7 Gold&Black ALPHA COUPE drill bits is built to tackle hard and stainless steels without yielding.

The Gold&Black drill bits drill, and the 5% Cobalt taps thread: a duo designed to work fast and straight, even on the toughest materials.

14 tools in one single set, zero compromise on cutting precision.

Overview of the ALPHA COUPE set: 7 5% Cobalt taps and 7 Gold&Black drill bits

This set contains 14 tools selected for tapping and drilling hard steel. Two complementary families: taps enriched with 5% cobalt and drill bits with a Gold&Black coating, designed to work together on the same materials.

The ALPHA COUPE 5% Cobalt taps handle stainless steels, alloy steels, and abrasive materials. The cobalt reinforces thermal resistance and delays wear of the cutting edge, even at high production rates.

The Gold&Black drill bits combine a double-layer surface treatment: the gold layer (titanium nitride) improves hardness, while the black layer reduces friction. Result: less heat, less seizing, better service life.

Detailed contents of the set and available dimensions

The set covers the 7 most common metric diameters in the workshop, from M3 to M12. Each diameter is represented by a matching drill bit and tap.

• Gold&Black drill bits: Ø 2.5-3.3-4.2-5-6.8-8.5-10.2 mm
• 5% Cobalt taps: M3, M4, M5, M6, M8, M10, M12
• Taps with cylindrical shank, ISO metric thread
• Drill bits with cylindrical shank, 118° point angle
• Rigid storage case included

Each drill bit is sized to prepare the hole before tapping, according to ISO tolerances for metric threads. No need to look up dimensions: the combination is already matched.

Feature	ALPHA COUPE Gold&Black Drill Bit	Standard HSS Drill Bit	Classic TiN Drill Bit
Coating	Double layer TiN + black	None	Single layer TiN
Friction reduction	High	Low	Medium
Thermal resistance	Good	Limited	Fair
Stainless / alloy steel	Yes	Not recommended	Partial
Associated 5% Cobalt tap	Yes (set)	No	No

5% Cobalt taps: why cobalt changes everything for tapping hard steel

A standard HSS tap in stainless or treated steel will break. Fast. 5% Cobalt (HSS-Co5) changes the game.

Adding cobalt to the high-speed steel grade increases the tap's hot hardness. When friction increases the temperature during tapping, the tool holds up. It does not blunt, it does not deform.

Concrete result: you can tap materials that standard HSS cannot handle, stainless steels, treated steels, high-strength steels, and hard cast irons.

Wear resistance is also significantly higher. An HSS-Co5 tap lasts significantly longer than an HSS tap on production runs in hard steel. Less breakage, less downtime, fewer rejected parts.

Grade	Hot hardness	Recommended materials	Relative longevity
HSS (M2)	Low	Mild steel, aluminum, plastics	Reference
HSS-Co5 (M35)	High	Stainless, treated, high-strength steels	+30 to +50 %
HSS-Co8 (M42)	Very high	Superalloys, titanium, Inconel	+60 to +80 %

The HSS-Co5 is the right compromise for workshops and general industry: performance on hard steel, controlled price, and immediate availability.

ALPHA COUPE Gold&Black drill bits: coating technology and drilling advantages

ALPHA COUPE Gold&Black drill bits stand out due to their double-layer coating: a gold-colored titanium nitride (TiN) base combined with a black finish from a specific heat treatment. This duo provides high surface hardness and reduces friction during drilling.

Concrete result: the heat generated during cutting is better dissipated. The cutting edge remains effective for longer, even on standard construction steels or medium-hard steels.

The geometry of these drill bits is optimized for production drilling. The 118° or 135° point angle, depending on the diameter, ensures precise centering and limits walking at the start of the hole.

These drill bits are designed to work in direct partnership with the 5% cobalt taps in the set. The diameter of each bit corresponds exactly to the pilot hole required for each tap: no calculations needed, no selection errors.

Feature	ALPHA COUPE Gold&Black drill bits	Standard HSS drill bits	5% HSS-Co drill bits (uncoated)
Coating	TiN + black treatment	None	None
Surface hardness	High	Low	Medium
Heat resistance	Good	Limited	Good
Recommended steels	Up to ~900 N/mm²	Mild steels	Up to ~900 N/mm²
Relative service life	High	Low	Medium to good

Comparison: ALPHA COUPE set vs. other tap/drill sets on the market

The market offers several combined tap + drill sets. Here is how the 5% cobalt ALPHA COUPE set compares to common alternatives.

Comparative table of available cobalt tap sets

Set	Tap material	Drill bit material	Cobalt content	Recommended use
ALPHA COUPE Gold&Black	5% Cobalt HSS	Gold&Black HSS (TiN)	5% Co	Hard steel, stainless, resistant alloys
Standard HSS set (generic)	HSS M2	HSS M2	0%	Mild steel, aluminum, plastic
8% Cobalt HSS-E set (e.g., Ruko, Dormer)	8% Co HSS-E	8% Co HSS-E	8% Co	Stainless, superalloys, titanium
Ground HSS-G set (e.g., Bosch, Makita)	HSS-G	HSS-G	0%	Standard steel, wood, plastic

5% Cobalt offers a good balance between hot hardness and impact resistance. It clearly outperforms standard HSS on hard steels and stainless steel.

Compared to 8% cobalt (Ruko, Dormer), the ALPHA COUPE is slightly less capable on extreme superalloys. However, for versatile workshop use, it is often better suited: less brittle, more tolerant to vibrations.

The Gold&Black treatment of the drill bits (titanium nitride) reduces friction and improves chip evacuation. Classic HSS-G sets do not offer this coating as standard.

At Dagobert Industrie, we offer this set for professionals who regularly work with structural steel, 304/316 stainless, or treated steels, without investing in solid carbide tools.

Applications and compatible materials: stainless steels, treated steels, and difficult alloys

The 7-piece 5% Cobalt tap set + 7 Gold&Black ALPHA COUPE drill bits is designed to attack materials that resist standard tools. Hard steels, stainless, difficult alloys: this is exactly where this set makes the difference.

The 5% cobalt content (HSS-Co5) of the taps improves heat resistance and hot hardness. The result: clean threads, even on austenitic stainless steel (304, 316) or treated steel with a high yield point.

The Gold&Black drill bits combine a double-layer surface treatment, nitriding + oxidation, which reduces friction and better dissipates heat. Ideal for drilling before tapping without burning the material.

Compatible materials:

• Stainless steels: 304, 316, duplex
• Treated and hardened steels up to ~45 HRC
• Structural steels (S235, S355) and alloy steels
• Grey and malleable cast irons
• Nickel alloys and light refractory steels

In maintenance workshops, boiler making, or precision mechanics, this set meets the demands of tapping in difficult materials without having to juggle between different brands of tools.

Feature	HSS-Co5 taps (this set)	Standard HSS taps	HSS-Co8 taps (e.g., Dormer E251)
Cobalt content	5 %	0 %	8 %
Hot hardness	Good	Low	Very good
Stainless steel	✔ Yes	Difficult	✔ Yes
Treated steel (< 45 HRC)	✔ Yes	✘ No	✔ Yes
Mild / structural steel	✔ Yes	✔ Yes	✔ Yes
Performance/cost ratio	Excellent	Good on mild steel	High

FAQ - 7-piece 5% Cobalt tap set + 7 Gold&Black ALPHA COUPE drill bits

1. Why choose 5% cobalt taps rather than classic HSS taps?

5% Cobalt (HSS-Co5) significantly improves heat and wear resistance compared to standard HSS.

On hard, stainless, or high-manganese steels, classic HSS taps blunt quickly. With cobalt, the service life is significantly longer.

2. What is the purpose of the Gold&Black treatment on ALPHA COUPE drill bits?

The Gold&Black treatment combines two layers: a gold layer (titanium nitride) for hardness, and a black finish to reduce friction and adhesion.

Result: the drill bits enter the material more easily, heat up less, and last longer than raw HSS drill bits.

3. Is this set suitable for stainless steel?

Yes, under specific conditions. Austenitic stainless steel (304, 316) remains drillable and tappable with this set, provided you work at reduced speeds and with appropriate lubrication.

For long production runs on thick stainless steel, tools specifically dedicated to stainless steel will perform better.

4. Which diameters are included in the set?

The set includes 7 matching drill bits and 7 taps, covering common metric threads, typically from M3 to M12.

Each drill bit is sized to prepare the pilot hole for the associated tap, the duo is ready to use with no additional calculation needed.

5. Can these tools be used on a drill press or only by hand?

ALPHA COUPE Gold&Black drill bits can be used on a drill press, portable drill, or light milling machine.

The taps can be used by hand (with a tap wrench) or by machine with a torque-limiting tapping chuck. Machine tapping improves thread consistency.

6. Is lubrication mandatory when drilling and tapping?

On standard steel, lubrication is highly recommended. On hard steel or stainless steel, it becomes indispensable to avoid overheating and seizing.

At Dagobert Industrie, we recommend using a cutting oil or a lubricant spray suitable for ferrous metals to maximize the set's service life.