Milwaukee Diamond Plus Hole Saw: The 20X Advantage in Porcelain and Stone

The Diamond Plus (now Diamond Max) delivers up to 20X longer life than standard diamond saws through vacuum-brazed grit technology and higher-grade diamonds. That’s not marketing fluff — it’s the difference between drilling three bathroom renovations versus drilling thirty before replacement.

Skip it if you’re drilling wood or metal. This tool exists for one reason: cutting through porcelain tile, natural stone, and glass without burning through bits every few holes. At 1-1/8” diameter with 1.5” cutting depth, it handles standard plumbing penetrations perfectly.

Diamond Technology That Actually Lasts

The vacuum-brazed diamond grit with superior retention changes the economics of tile work. Traditional diamond bits lose their grit through heat and friction — you’ve seen them go smooth and useless halfway through a job. Milwaukee’s vacuum brazing bonds each diamond particle deeper into the steel substrate.

Higher-grade industrial diamonds resist heat and fracture better than standard grit. When you’re drilling granite countertops at a Whitefish ski lodge or porcelain tile in a Bozeman master bath, that heat resistance translates directly to more holes per bit.

The performance numbers tell the story:

Specification	Value
Diameter	1-1/8” (28.6 mm)
Cutting depth	1.5 inches (38 mm)
Maximum RPM	2100
Recommended RPM (porcelain/stone)	500-800
Shank type	1/4” Quick-Change Hex

Speed Control Makes or Breaks Performance

Do not exceed 2100 RPM. Heat is the enemy of diamond grit. Most contractors learn this lesson the expensive way — spinning too fast turns a premium bit into scrap metal in minutes.

Wet cutting is strongly recommended for maximum life. Submerge the bit in water before each cut and apply water during the process. Yes, it’s messier. Yes, it takes more setup. But wet cutting can triple your bit life on hard materials.

Start at a 45-degree angle to create a ‘groove’ then gradually bring the bit to 90 degrees. This technique prevents the walking that ruins tile surfaces and frustrates installers. The self-starting capability reduces walking, but proper technique still matters.

Real Limitations Worth Knowing

Rapid wear occurs if used at high speeds or without water. Clogging happens in thick porcelain if not cleaned frequently. Some batches reportedly lack the ejection slot, making plug removal difficult — check your bit before heading to the jobsite.

Customer reviews average 3.2 out of 5 stars based on official site and retailer listings. That’s honest feedback from contractors who push these bits hard. The negative reviews consistently point to the same issues: running too fast, skipping water cooling, or expecting miracles on 2-inch thick granite.

Who Should Buy This

Worth it for bathroom remodelers, tile installers, and plumbers who regularly penetrate porcelain and stone. The large slug ejection slot speeds up repetitive drilling. The 1/4” hex shank fits standard quick-change arbors on any drill or impact driver.

Skip it for occasional DIY use. A carbide bit costs half as much and works fine for one or two holes. But for contractors billing by the job, not by the hour, the Diamond Plus pays for itself through speed and longevity.

Compatible materials include porcelain tile, ceramic tile, granite, marble, natural stone, glass, slate, and fiberglass. That covers 90% of what Montana contractors encounter in high-end bathroom and kitchen work.

FAQ

What’s the actual lifespan difference between Diamond Plus and standard diamond bits?

Up to 20X longer life versus standard diamond saws with the current Diamond Max version, or 10X for the older Diamond Plus version. Real-world results vary based on material hardness and cutting technique.

Is dry cutting possible, or is water absolutely necessary?

The bit is optimized for both wet and dry applications, but wet cutting is recommended for maximum life. Dry cutting works but significantly reduces bit lifespan, especially on hard porcelain or granite.

What RPM delivers best results?

Maximum 2100 RPM rating, but 500-800 RPM is recommended for very hard materials like porcelain or stone. Lower speeds extend bit life dramatically.

Does this work with impact drivers?

Yes, it’s compatible with impact drivers using a hex adapter. The 1/4” hex shank fits standard quick-change arbors.

What’s the warranty coverage?

Milwaukee warrants accessories for defects in material or workmanship. This does not cover normal wear and tear from use. Some retailers list it as ‘No Warranty’ for consumable items, but Milwaukee generally backs manufacturing defects.