Name: 7 degree taper chisel drill bit with tungsten carbide
Brand: beentools

Description

Key Features:

This taper drill bit is forged from 45CrNiMoV alloy steel, offering higher toughness and effectively preventing breakage of the 7 degree taper chisel drill bit.
Designed with flushing holes to efficiently discharge cuttings, waste fluid, and air bubbles, preventing jamming.
7 degree taper angle for a tight fit with taper drill rods, ensuring efficient operation.

Technical Specifications of 7 Degree Taper Chisel Drill Bit

Bit diameter: 32 mm, 34 mm, 36 mm, 38 mm, 40 mm, 42 mm, and 43 mm available
Tungsten carbide inserts: 13×8 mm, 15×8 mm, 13×9 mm, 15×10 mm, and 17×10 mm available
Taper: 7 degree
Weight: 0.2 kg to 0.5 kg

Recommendations for Use

Ensure the taper bore of the bit and the taper of the drill rod are clean, and both are 7 degree taper.
Ensure sufficient flushing water and air pressure to remove cuttings, waste fluid, and air bubbles, and to cool the bit.
Allow the bit to cool naturally. Do not quench it in cold water to prevent thermal cracking.
If the taper surface is abnormal, regrind immediately to prevent stress fracture.
The bit diameter should match the drill rod requirements.

Main Applications

7 degree taper chisel drill bits are widely used for small-hole blasting drilling in underground mines, and for small-diameter drilling in marble, granite, and aggregate production.

FAQ (Frequently Asked Questions)

Should I choose a chisel bit or a button bit?

Taper chisel drill bits are suitable for small-hole drilling in soft to medium-hard rock. They are lower in cost and easier to regrind the cutting edge. Taper button drill bits are used for very hard or highly abrasive rock such as granite. They offer higher drilling efficiency and greater durability.

Should I choose a 7-degree, 11-degree, or 12-degree taper drill bit?

The taper angle of the taper drill bit must exactly match the taper angle of the drill rod you are using. If you do not know the exact taper, check the markings on your drill rod or equipment, or measure the rod’s taper, length, and shank diameter. Using a mismatched taper will result in damage to the bit or the rod. Typically, 7-degree taper drill bits are used for lightweight, handheld rock drills such as the YT24 or Y26, mainly for small-hole drilling.

What is the 3mm rule for regrinding taper chisel drill bits?

When the width of the wear flat on the cutting edge of the taper chisel drill bit reaches 3mm, the tungsten carbide edge should be reground. Continuing to use a blunt bit will increase stress on the chisel bit, which may lead to the bit fracturing.

Can this taper chisel drill bit be used with both air and water flushing?

Absolutely. The 7 degree taper chisel drill bit is designed with flushing holes, allowing for efficient discharge of cuttings, waste fluid, and air bubbles, preventing the bit from overheating or jamming during operation.

How can I prevent the carbide insert from falling out of the drill bit?

Make sure the taper of the drill bit and the drill rod are perfectly matched for a tight fit. Always use flushing fluid and never drill dry. These practices can prevent the drill bit from overheating and reduce the risk of the carbide insert falling out during operation.

Technical Parameters 1

7 degree taper chisel drill bit with tungsten carbide
Taper bit, Insert	D		Insert H x T	Taper	Order number	Weight kg
Taper bit, Insert	mm	inch	Insert H x T	Taper	Order number	Weight kg
Chisel	32	1 1/4	13 x 8	7 degree	B118-3213-2710	0.2
	32	1 1/4	15 x 8	7 degree	B118-3215-2710	0.2
	34	1 11/32	13 x 8	7 degree	B118-3413-2710	0.3
	34	1 11/32	15 x 8	7 degree	B118-3415-2710	0.3
	36	1 13/32	13 x 8	7 degree	B118-3613-2710	0.3
	36	1 13/32	15 x 8	7 degree	B118-3615-2710	0.3
	38	1 1/2	13 x 9	7 degree	B118-3813-2710	0.3
			15 x 10		B118-3815-2710	0.3
			17 x 10		B118-3817-2710	0.4
	40	1 9/16	13 x 9	7 degree	B118-4013-2710	0.3
			15 x 10		B118-4015-2710	0.4
			17 x 10		B118-4017-2710	0.4
	42	1 5/8	13 x 9	7 degree	B118-4213-2710	0.4
			15 x 10		B118-4215-2710	0.4
			17 x 10		B118-4217-2710	0.5
	43	1 5/8	13 x 9	7 degree	B118-4313-2710	0.4
			15 x 10		B118-4315-2710	0.4
			17 x 10		B118-4317-2710	0.5

Technical Parameters 2

comparison between Taper Chisel Bit and Taper Button Bit
Feature	Taper Chisel Bit	Taper Button Bit
Design	Single wedge-shaped carbide blade	Multiple hemispherical or conical carbide buttons
Best Rock Type	Soft to Medium-Hard (e.g., Limestone, Sandstone)	Hard to Very Hard & Abrasive (e.g., Granite, Basalt, Quartzite)
Drilling Speed	Very fast in soft rock; slows significantly in hard rock	Consistent high penetration rates across various rock types
Hole Straightness	Prone to deviation in fractured / broken ground	Excellent stability; straighter, cleaner holes
Flushing Efficiency	Moderate to poor: Larger, flatter cuttings can clog in fractured rock; more regrinding of debris	Superior: Smaller, uniform cuttings + better exposure of flushing paths → faster cuttings removal, less clogging, cooler bit operation
Maintenance	High: Frequent regrinding required to maintain sharp edge	Low to maintenance-free; much less frequent grinding needed
Initial Cost	Lower: Economical for small-scale or budget projects	Higher upfront but longer service life & lower cost per meter
Risk of Jamming	Higher risk in fissured or broken rock	Lower risk due to multiple contact points & better flushing

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7 degree taper chisel drill bit with tungsten carbide