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3M Cubitron Sanding Disc Buying Guide: Film, Hookit, Paper, and Stikit

3M 732U Cubitron II Stikit Paper Disc, 80+ C-weight, 5 in x NH, Linered w/Tab, Die 500X (7100044453)

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Table of contents

What Is Cubitron Technology? 3M Cubitron Film Discs 3M Cubitron Paper Discs 3M Cubitron Hookit Discs: Understanding the Attachment System 3M Cubitron Stikit Discs: The PSA Format How to Choose the Right Cubitron Disc for Your Job Grit Selection Reference Final Thoughts Frequently Asked Questions

If you've spent any time grinding, finishing, or doing surface prep on the job, you already know that not all sanding discs are created equal. Some cut fast but burn out quick. Some last forever but barely scratch the surface. And some just don't hold up when you're working with stainless steel, hardened steel, or aluminum.


That's where 3M Cubitron discs come in. 3M has built a reputation in the trades for cutting faster and lasting longer than most conventional abrasives. But with multiple product lines including film, Hookit, standard paper, and Stikit options, it can get confusing fast. 

Each one has a specific purpose, and using the wrong disc for the job means slower work, more consumables, and more money out of your pocket.


This guide breaks down each type of 3M Cubitron sanding disc, what makes them different, and when you should be reaching for one over another.

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What Is Cubitron Technology?

Before getting into the specific disc types, it helps to understand what makes Cubitron abrasives different from standard aluminum oxide or ceramic discs.


3M Cubitron and Cubitron II discs use what 3M calls Precision Shaped Grain (PSG). Instead of irregular, randomly shaped abrasive particles, the grain is engineered into uniform, triangular points. Think of it like the difference between dragging a dull rock across a surface versus using a sharp blade.


Traditional abrasive grains are blocky and rounded. Over time they dull, then they start rubbing and generating heat instead of cutting. PSG grains are different. Because of their triangular shape, as the tip of each grain wears down, a fresh cutting edge is exposed. The grain keeps cutting sharp for much longer than conventional ceramic or aluminum oxide abrasives.


The result, according to 3M, is that Cubitron II grain cuts at least 30% faster and lasts at least 30% longer than traditional ceramic abrasives. That claim holds up in most shop environments and real-world applications, especially in metalworking and fabrication.


Now let's look at how that grain technology is applied across the different disc formats.

3M Cubitron Film Discs

3M 3M 775L Cubitron II Hookit Film Disc, 320+, Purple, 3 in, 300DS 53-Hole (7100145433) (250 Pack)
What They Are

Film-backed discs use a polyester film substrate instead of paper or fabric. That might not sound like a big deal, but it changes the disc's performance characteristics significantly.

The film backing is thinner and more flexible than paper. It's also more durable and tear-resistant, which matters when you're working on surfaces that aren't perfectly flat or when you're running the disc at high speeds on a random orbital sander. All 3M Cubitron II film discs are 3 mil thick, which gives them consistent flex and durability across the product line.

Film-backed Cubitron discs are coated with micron-graded minerals and built specifically for fine finishing applications. You'll see them used in applications that require a consistent, controlled scratch pattern and a smooth final surface.

Common Applications

Film Cubitron discs are a go-to for:

  • Fine finishing on metal and painted surfaces
  • Automotive body work and paint prep
  • Finish sanding on composite materials
  • Applications where scratch depth control matters
  • Preparing surfaces for primer, sealer, or topcoat
The Xtract vs. Standard 775L

Within the film disc lineup, you'll notice two sub-families: standard 775L discs and 775L Xtract discs. The difference comes down to dust extraction.

Xtract discs have a multi-hole pattern designed to work with dust-extracting sanders. If your sander has built-in vacuum extraction, the Xtract series pulls dust away from the surface as you work. That keeps the disc cooler, reduces loading, and keeps your workspace cleaner. For bodywork and finishing environments where airborne particulate is a real concern, Xtract discs are worth using if your setup supports them.

Standard 775L film discs are the go-to when you're not running dust extraction, or when you need a simpler hole pattern for your specific backup pad.

Hookit Film Disc Options

Most film discs in the Cubitron line use hook-and-loop (Hookit) attachment. Here's a breakdown of what's available:

3-inch Hookit film discs are built for detail work and tighter access. The 3M 775L Cubitron II Hookit Film Disc comes in 80+ (7100106742), 120+ (7100106764), 180+ (7100106768), 220+ (7100106716 / 7100106766), and 320+ (7100145433) grits. These are available in packs of 250 and use the 300DS or 300V die patterns.

5-inch Hookit film discs are the most common size you'll find in body shops and finishing environments. 

Options include:

6-inch Hookit film discs cover the larger-format random orbital work. The Xtract 6-inch lineup includes:

Stikit Film Disc Options

If your setup uses pressure-sensitive adhesive backing rather than hook-and-loop, the 775L line also comes in Stikit format:

What to Know Before You Buy

Because film discs are designed for fine finishing, they typically run in finer grits than what you'd use for heavy material removal. They're not the right choice for blending welds or grinding down a rough surface. Save those jobs for a coarser paper or fiber disc.

The main advantage of film over paper in finishing work is consistency. Film discs tend to produce a more uniform scratch pattern, which shows up as better surface quality when you apply a coating. If final finish quality matters on your project, film-backed discs are worth the extra cost.

3M Cubitron Paper Discs

3M Cubitron Paper Discs
What They Are

Paper-backed sanding discs are the most common format you'll find on the job. They're flat, circular abrasives attached to a paper backing instead of a film or fabric backing. You'll see these used on random orbital sanders, angle grinders, and disc sanders across construction, fabrication, automotive, and finishing work.

3M Cubitron paper discs bring PSG technology to that standard format. The backing is C-weight paper, which gives the disc enough stiffness for aggressive stock removal while still providing some flex for slightly curved surfaces.

Common Applications

Paper-backed Cubitron discs work well for:

  • General metal fabrication and grinding

  • Weld blending and seam work

  • Deburring and edge work on steel

  • Surface conditioning before coating or painting

  • Wood material removal where you need speed without burning the surface

Paper Disc Options: Hookit Format (732U)

The 3M 732U is the main Cubitron II paper disc series. In Hookit format, these come in both standard and clean-sanding versions:

5-inch Hookit paper discs:

6-inch Hookit paper discs:

The 737U Clean Sanding versions are designed for sanders with dust extraction. They're available in 3-inch (40+ and 80+ grit, packs of 200) and 6-inch formats covering 40+, 80+, 120+, 220+, 320+, 600+, and 800+ grits. If you're doing production finishing work or working indoors where dust control matters, the clean-sanding versions pair well with an extraction system.

For shops running the very fine grits on orbital sanders, the 737U line extends all the way up to 800+ grit (7100330728 in 6-inch, 7100329992 in 3-inch), which is uncommon for paper discs and puts this series firmly in the refinishing and defect-removal category.

Stikit Paper Disc Options (732U and 216U)

For PSA-attached paper discs, the 732U Stikit line covers the most common grit and size combinations:

5-inch Stikit paper discs (732U):

6-inch Stikit paper discs (732U):

The 3M 216U Cubitron II Stikit Gold Paper Disc Roll is a different format worth mentioning. These come as disc rolls with 75 to 175 pre-cut discs per roll, designed for high-volume sanding operations. They come in P220 (7100080109), P360 (7000118106), and P400 (7000028092) grits in 5-inch and 6-inch sizes. The roll format makes dispensing fast in a production environment where you're going through discs continuously.

What to Know Before You Buy

Paper backing is durable but has its limits. It doesn't handle moisture well. If you're working in wet environments or doing wet sanding, film-backed discs handle those conditions better.

Also pay attention to the hole pattern designation before ordering in bulk. The same grit and size can come in multiple hole patterns (500X, 500FH, 500LG, 600Z, 600HZ, 600LG, 300V, 300DS), and you need to match the hole pattern to your backup pad. Getting this wrong means the dust ports on your sander don't line up with the disc, which defeats the purpose of clean-sanding versions.

3M Cubitron Hookit Discs: Understanding the Attachment System

3M Cubitron Paper Discs
What It Is

Hookit is 3M's proprietary hook-and-loop attachment system. Instead of using adhesive to stick the disc to a backup pad, Hookit discs use a hook-and-loop connection. The disc has loop material on the back, and it attaches to a backup pad that has hook material on the face.

You can peel a Hookit disc off the pad and reattach it as needed, which makes swapping grits faster and easier. There's no adhesive to worry about, and you don't have to worry about the disc sliding or losing attachment after a few uses.

The Cubitron Hookit lineup covers three backing types: paper (732U), cloth (947A), and film (775L). This makes Hookit more than just an attachment method. It's also the broadest platform in the Cubitron line.

Cloth Disc Options (947A)

The 3M 947A Cubitron II Hookit Cloth Disc uses X-weight cloth backing, which is more durable than paper and better suited for aggressive metalworking. These are available in maroon and come in 3-inch, 5-inch, and 6-inch sizes:

3-inch cloth discs: 80+ grit (7100113126)

5-inch cloth discs:

6-inch cloth discs:

Cloth-backed discs are the choice when you need aggressive material removal on hard metals and you need the disc to hold up under pressure. They won't conform to complex shapes as well as film discs, but for flat work and edge grinding, the X-weight cloth backing handles abuse that would tear a paper disc apart.

Common Applications

Hookit discs work well anywhere you're changing grits frequently or where disc removal and replacement speed matters:

  • Body shops and paint prep work

  • Woodworking and cabinet shops

  • Multi-step finishing operations where you're running through several grits on the same part

  • Shops where multiple people are using the same sanders and swapping discs throughout the day

  • Situations where the same tool and pad needs to do both heavier and finer work

What to Know Before You Buy

To use Hookit discs, your backup pad has to be compatible. If your sander came with a PSA-style pad, you'll need to swap it out for a Hookit pad. Most manufacturers make both versions, and replacement pads are widely available.

One thing worth noting: the hook-and-loop connection is only as good as the pad condition. If your backup pad's hook material is worn down, clogged with debris, or damaged, Hookit discs won't hold as securely. Keep your pads clean and replace them when they start losing grip.

3M Cubitron Stikit Discs: The PSA Format

3M 87337 Cubitron II Stikit Film Disc, PSA Multi-Grade 80+ to 220+, Purple, 5 in x NH, 3 mil (7010363665)
What It Is

Stikit is 3M's brand name for their pressure-sensitive adhesive disc system. Stikit discs have a pre-applied adhesive on the back side. You peel off a liner and press the disc onto a smooth backup pad. The disc sticks in place and stays put during operation.

Stikit discs are a common choice in production environments where speed of attachment matters and operators need to keep moving. They're also popular where the sander or machine already has a smooth, non-Hookit backup pad.

The 3M Cubitron Stikit lineup includes both paper-backed (732U) and film-backed (775L) options, plus the 216U Stikit Gold disc rolls mentioned above.

What to Know Before You Buy

PSA discs are meant to be used once and replaced. Unlike Hookit, you can't peel a Stikit disc off and reattach it cleanly. The adhesive degrades, the backing may tear, and you'll end up with a disc that doesn't hold properly if you try to reuse it.

That said, PSA discs often cost less per unit than Hookit discs, which makes them a reasonable choice in applications where you're going through a lot of discs quickly and reusability isn't a priority.

Backup pad condition matters just as much with Stikit as with Hookit. A dirty, contaminated, or worn pad won't hold a Stikit disc reliably. Keep the pad surface clean and replace it when it shows wear.

How to Choose the Right Cubitron Disc for Your Job

With four different formats and dozens of grit options within each, it helps to have a simple decision process. Here's how most experienced tradespeople think through it.

Step 1: What Are You Trying to Accomplish?

Heavy stock removal, weld blending, deburring, and grinding all call for a coarser grit and typically a paper or cloth backing. If you're knocking down material fast, start coarse and work your way up.

Fine finishing, paint prep, and applications where scratch control matters call for film-backed discs in finer grits. The film backing gives you better conformability and scratch pattern consistency at those finer grits.

Step 2: How Does Your Tool Attach Discs?

If your backup pad uses a hook-and-loop system, you want Hookit discs. If your pad is smooth and uses adhesive-backed discs, you want Stikit. Using the wrong attachment type means the disc won't hold properly, which is both a quality issue and a safety issue.

Step 3: How Often Are You Changing Grits?

If you're constantly swapping between grits during a job, Hookit is more efficient. The peel-and-stick operation on PSA discs slows you down when you're doing it ten times a day.

If you're running the same grit all day on a production piece, Stikit's lower per-disc cost makes more sense.

Step 4: Do You Need Dust Extraction?

If you're running a dust-extracting sander, look for the "Clean Sanding" or "Xtract" designation in the product name and make sure the hole pattern on the disc matches your sander's port layout. The main patterns in the Cubitron lineup are 500LG, 600LG (multi-hole), 300DS (53-hole), 500FH (5-hole), and 600HZ (6-hole). Getting this matched up correctly makes a real difference in dust capture efficiency.

Grit Selection Reference

Here's a general reference for grit selection across typical trade applications:

  1. 36 to 60 grit: Heavy stock removal, grinding welds flat, surface conditioning on rough metal. You're taking material off fast. Surface finish isn't the priority. Cloth-backed or paper-backed discs at this range.
  2. 80 to 120 grit: Transitional work. Good for blending after a coarser grit, prepping surfaces before finishing, or light material removal on softer materials. Both paper and film options available in this range across the Cubitron lineup.
  3. 150 to 220 grit: Fine finishing on metal or wood. Prepping surfaces for primer or paint. At this range, film-backed Xtract discs tend to give better results than paper in terms of scratch consistency.
  4. 240 to 400 grit: Ultra-fine finishing. Mostly used in automotive and painted surface refinishing work. Film-backed discs dominate at this range. The 87435 multi-grade pack (240+/320+/400+) is a practical option for shops that need to cover this entire range without stocking three separate SKUs.
  5. 600 to 800 grit: Defect removal and finishing on paint and clear coat. The 737U clean-sanding discs extend into this range in both 3-inch and 6-inch formats, which is uncommon for coated abrasive discs and puts them in the same territory as traditional wet sanding applications, but without the water.

Final Thoughts

3M Cubitron discs have earned their place in professional shops and on jobsites because the technology behind them delivers real, measurable performance. The Precision Shaped Grain is a genuine advancement over conventional ceramic abrasives, and you'll feel the difference in how fast these discs cut and how long they last.

But the technology only helps you if you're using the right format for the job. Paper discs for stock removal and general finishing, film discs for fine finishing and surface prep, cloth discs for aggressive metalworking that demands a tougher backing, Hookit for fast grit changes and versatility, and Stikit for production environments where PSA attachment makes sense.

Understanding those differences means fewer wasted discs, better surface results, and less time spent fighting your consumables on the job. And with the range 3M has built into the Cubitron line, from 40+ grit cloth discs all the way up to 800+ grit clean-sanding paper discs, there's a configuration that fits whatever you're working on.

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Frequently Asked Questions

What is the difference between 3M Cubitron and Cubitron II?

Cubitron II is the second generation of 3M's Precision Shaped Grain technology. The grain geometry was refined to cut even faster and run cooler than the original Cubitron line. Most current products in the lineup carry the Cubitron II designation. If you're shopping today, you'll mostly find Cubitron II products, and they outperform the original in both cut rate and disc life.

Can I use a Hookit disc on a sander with a PSA backup pad?

No. Hookit discs require a hook-and-loop backup pad to attach properly. If your sander came with a smooth PSA pad, you'll need to swap it out for a Hookit-compatible pad before using Hookit discs. Replacement pads are available from most tool manufacturers and distributors.

What's the difference between Xtract and standard 775L film discs?

The main difference is the hole pattern. Xtract discs have a multi-hole layout designed to work with dust-extracting random orbital sanders. Standard 775L discs have fewer or no holes and are intended for use without vacuum extraction. If your sander has built-in dust collection, Xtract discs will pull more dust away from the surface, keep the disc cooler, and reduce loading. If you're not running extraction, stick with the standard 775L.

Are Stikit discs reusable?

No. Stikit discs use a pressure-sensitive adhesive backing that's designed for single use. Once you peel a Stikit disc off the backup pad, the adhesive won't bond cleanly a second time. Trying to reuse them leads to poor adhesion and disc failure during use. If you need a reusable option, go with Hookit.

What hole pattern do I need for my sander?

That depends on your specific sander. The most common patterns in the Cubitron lineup are 500X (no holes), 500FH (5-hole), 500LG (multi-hole Xtract), 600Z (no holes), 600HZ (6-hole), and 600LG (multi-hole Xtract). Check your sander's manual or the backup pad itself to confirm the pattern before ordering. If the disc holes don't line up with your sander's dust ports, you lose most of the dust extraction benefit.


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