Diablo DMAPL4170 3/8 Inch x 16 Inch x 18 Inch Rebar Demon SDS-Plus 4-Cutter Full Carbide Head Hammer Drill Bit

Key Features

Built for RebarThe full carbide 4-cutter head is made to keep drilling when you hit rebar. Instead of chipping out fast like a basic 2-cutter bit, it takes smaller bites for better control and longer service life. Cleaner, Truer HolesThe precision tip and reduced-vibration cutting action help the Diablo DMAPL4170 hammer drill bit start straight and stay on line. That matters when you are drilling anchor holes in reinforced concrete and do not want to fight the bit. Longer Bit LifeDiablo rates this Rebar Demon SDS-Plus 4-Cutter Full Carbide Head Hammer Drill Bit for up to 7X longer life than standard 2-cutter hammer drill bits. More carbide, stronger welding, and faster dust removal all work together to keep the head intact under heavy impact.

Overview

The Diablo DMAPL4170 3/8 Inch x 16 Inch x 18 Inch Rebar Demon SDS-Plus 4-Cutter Full Carbide Head Hammer Drill Bit is a long-reach masonry drilling bit built for reinforced concrete, anchor setting, and drilling through material that may contain rebar. This is a hammer drill bit designed for drilling fast, precise holes in concrete and concrete with rebar. Model Number: DMAPL4170. With a 3/8 inch diameter, 16 inch working length, and 18 inch overall length, it is aimed at users who need deeper holes without giving up control at the tip.

What separates this bit from a basic masonry bit is the head design. Diablo uses a 4-cutter full carbide head that is meant to keep working when the bit encounters rebar instead of stalling out, chipping, or walking off line. The brand also calls out up to 7X longer life versus standard 2-cutter hammer drill bits. On the job, that means fewer burned-up bits when you are drilling repeated anchor holes in reinforced concrete, block, brick, stone, or natural stone.

The carbide package matters here. Diablo states that its Dura-Carbide construction uses up to 2X more carbide and can withstand temperatures up to 1800 degrees Fahrenheit, compared to standard bits that fail around 800 degrees Fahrenheit. If you drill in dense concrete or regularly clip rebar, heat is what kills bits. More heat resistance and more carbide give this SDS-Plus bit a better shot at staying usable under abuse instead of rounding over early.

Diablo also uses what it calls Tri-Metal Fusion Welding to keep the full carbide head attached during extreme impact. That is not just brochure talk on a bit like this. Long bits see a lot of stress because the farther out you drill, the more leverage and vibration you create. A stronger weld between the carbide head and the body helps the bit survive those hard hits that show up in reinforced slabs and structural concrete.

Hole quality is another strong point. The precision tip is there to help the bit start accurately and stay stable as it cuts. Diablo says the 4-cutter head takes smaller bites of rebar for controlled carbide wear and reduced vibration. In plain terms, that means straighter starts, less chatter, and more consistent hole size, which is exactly what you want when the hole needs to match the anchor and the embedment depth actually matters.

Flute design is doing real work too. Diablo calls out an optimized flute that removes dust faster and keeps the carbide head cooler. That improves drilling speed in concrete and helps reduce the heat buildup that shortens bit life. There is also a wear mark indicator to help you maintain accurate hole making over the life of the bit. For concrete fastening, that is useful because worn bits can drill oversized holes that hurt anchor performance.

The shank is SDS Plus, so this bit is built for SDS-Plus rotary hammers. Diablo also notes the design is optimized for maximum performance in corded and cordless rotary hammers. For a contractor or serious DIY user already running an SDS-Plus platform, that makes this an easy fit for deep concrete drilling, retrofit work, and mechanical anchor installs where reach and durability matter more than bargain-bin price.

This is a good choice for concrete contractors, electricians, mechanical trades, general contractors, and remodelers who drill repeated holes in reinforced concrete and do not want to treat bits like disposable items. If your work is mostly shallow holes in soft block, a simpler bit may get it done. If you routinely hit rebar or need a long 3/8 inch bit that can stay accurate, this is the kind of bit worth buying once instead of replacing twice.

Deep Reach for Reinforced Concrete Drilling

Long masonry bits only earn their keep if they stay accurate at depth. The Diablo DMAPL4170 is built around a long 16 inch working length, a full carbide head, and a flute design that clears dust fast so the bit keeps cutting instead of polishing the hole.

• 3/8 inch diameter for concrete fastening and anchor-hole work
• 16 inch working length and 18 inch overall length for deeper drilling reach
• 4-cutter full carbide head helps manage rebar strikes with less vibration

Key Specifications

Diameter	3/8 in
Overall Length	18 in
Working Length	16 in
Shank Type	SDS Plus
Head Type	Full Carbide Head
Number of Cutters	4
Pack Quantity	1
Weight	0.4 lb

Compatibility

Rotary Hammer InterfaceSDS Plus shank for use with SDS-Plus rotary hammers. Tool Power TypeOptimized for maximum performance in corded and cordless rotary hammers.

Built For

Concrete Concrete with Rebar Reinforced Concrete Anchor Setting Masonry Electrical General Contracting Remodeling

Pro Tip

If you are drilling repeated anchor holes, keep an eye on the wear mark indicator. It is a quick way to catch a worn bit before it starts making holes that are out of spec for the anchor.

Tool Nut’s Take

Tool Nut’s Take

Diablo DMAPL4170 Hammer Drill Bit for Guys Who Actually Hit Rebar

The Diablo DMAPL4170 3/8 Inch x 16 Inch x 18 Inch Rebar Demon SDS-Plus 4-Cutter Full Carbide Head Hammer Drill Bit makes sense when cheap concrete bits keep dying the second the job gets real.

• Who it’s for: Pros and serious DIY users drilling deeper anchor holes in reinforced concrete, especially when rebar strikes are part of the day.
• Why it stands out: The 4-cutter full carbide head, extra heat resistance, and stronger head welding are aimed at the exact problems that kill standard masonry bits.
• Worth knowing: This is an SDS Plus bit with a long 16 inch working length, so it is built for rotary hammer work and deeper holes, not casual drilling with a standard hammer drill chuck.

Common Questions

• What material is this bit designed to drill? It is designed for reinforced concrete, concrete, block, brick, stone, natural stone, and concrete with rebar.
• What shank does this bit use? It uses an SDS Plus shank.
• How long is the usable drilling section? The working length is 16 inches, with an overall length of 18 inches.
• What makes this different from a standard 2-cutter masonry bit? Diablo specifies a 4-cutter full carbide head, up to 2X more carbide, and up to 7X longer life versus standard 2-cutter hammer drill bits.