You're halfway through a sanding job and the disc won't hold. Maybe it slides around on the pad after a few passes. Maybe it won't grip at all. A lot of that headache comes down to one simple thing: you grabbed the wrong disc for your pad. 3M makes two different sanding disc attachment systems, Hookit and Stikit, and they don't run on the same setup. Knowing which one you're working with, and why it's built that way, saves you time, money, and a trip back to the supply house.
Both systems do the same basic job. They hold an abrasive disc onto a backup pad so you can sand wood, metal, body filler, paint, or just about anything else that needs smoothing before the next step. The difference is how the disc attaches to that pad, and that one detail changes how you work, how often you swap discs, and what kind of finish you end up with.
What Is 3M Hookit?
Hookit is 3M's hook-and-loop attachment system. It works the same way as Velcro. The backup pad on your sander has a face covered in small, stiff hooks. The back of a Hookit disc has a soft loop fabric. Press the two together, and they lock in place. Pull the disc back off, and they let go clean, with no tape, no screws, and nothing left behind on the pad.
That quick-change design is the whole point of Hookit. Say you're working a panel that needs three or four grits to go from rough to finished. With a hook-and-loop system, you pull off one disc and press on the next in a few seconds flat. No tools, no mess. Since the disc comes off clean, you can usually reuse it later if it's still got life left in it. Over a full job, that adds up to real savings compared to a disc you can only use once.
Hookit discs run on random orbital and dual-action sanders, the kind most trade pros already own. They come on paper, film, and cloth backings, plus specialty options like Clean Sanding discs built with dust-channeling holes for use with a vacuum-equipped sander. Here's a sample of the Hookit discs and pads Pro Work Supply carries.
Shop 3M Hookit Discs
What Is 3M Stikit?
Stikit is 3M's pressure-sensitive adhesive system, usually shortened to PSA. Instead of hooks and loops, the back of a Stikit disc carries a layer of adhesive under a paper liner. Peel the liner off, press the disc onto a smooth, hard-faced pad, and it bonds on contact. No hook fabric needed on either side, just a clean adhesive bond, similar to how a sticker or double-sided tape mounts to a surface.
That flat, direct contact is Stikit's biggest strength. Because the disc sits right against a rigid pad with no cushion of loop fabric in between, it stays flatter across the whole face. That matters most on flat panels, auto body filler, and other surfaces where you don't want the edges of the disc digging in or rounding over the work. A lot of shops that run the same grit for a long stretch reach for Stikit for exactly that reason. It's just as rigid as it needs to be, and it does the job at a lower cost per disc than a comparable Hookit disc.
The tradeoff is reuse. Once you peel a Stikit disc off the pad, dust and grit work into the adhesive and it won't stick reliably a second time. Most shops treat Stikit discs as single-use. Changing grits also takes a little longer, since you're peeling a liner and pressing on a fresh disc instead of just pulling one off and snapping another one on. That lower price per disc is the tradeoff for giving up quick reuse.
Stikit shows up a lot on air-powered and stationary disc sanders, and it also comes on rolls fed through a wall-mounted or bench dispenser, which makes sense for shops burning through a lot of one grit at a time. Here's a sample of the Stikit discs and dispenser Pro Work Supply carries.
Shop 3M Stikit Discs
Hookit vs. Stikit Side by Side
Here's how the two systems stack up when you put them next to each other. Trade publication Pro Tool Reviews sums up the tradeoff well: "Hook and loop discs are reusable, so you can use them until the abrasives are fully spent, saving you money in the long run." On PSA, they add that it "tend[s] to hold more securely to the pad than hook and loop discs. The downside is that the discs aren't reusable, including if you misalign the dust holes."
| Attribute | 3M Hookit (Hook-and-Loop) | 3M Stikit (PSA) |
|---|---|---|
| Attachment | Loop fabric on disc grips hooks on the pad | Pressure-sensitive adhesive bonds to a smooth, hard pad |
| Reuse | Reusable, peel off and reapply if the disc still has life | Single-use, adhesive fouls once you peel it off |
| Grit change speed | A few seconds, pull off and press on the next | Slower, peel the liner and press on a fresh disc |
| Surface contact | Slight give from the pad, follows mild curves | Flat and rigid, resists rounding edges on panels |
| Best fit | Frequent grit changes, curves, RO and DA sanders | Flat panel leveling, long single-grit runs, air/stationary sanders |
| Cost pattern | Higher price per disc, offset by reuse over a job | Lower price per disc, but every disc is a one-time cost |
| Tools/setup | Backup pad or interface pad with a hook face | Smooth hard-faced pad, or a roll dispenser for sheet stock |
How to Choose Between Hookit and Stikit
There's no single right answer here. It comes down to the job in front of you and the sander you're running. Use these as a starting point.
- You change grits often on the same piece: Hookit lets you swap discs in seconds with no tools and no adhesive mess.
- You're leveling flat panels, filler, or lacquer: Stikit's flat, rigid contact resists rounding the edges of the work.
- You want to reuse discs to cut cost over a full job: Hookit is built for that. Stikit isn't meant to come back off and reattach.
- You're running one grit for a long production stretch: Stikit's lower per-disc price adds up in your favor.
- You're working curves, contours, or body lines: A Hookit interface pad adds a little conformability that follows the shape without digging in.
- Your sander already has one type of pad mounted: match the disc to the pad you've got. A Hookit disc won't grip a smooth PSA pad, and a Stikit disc won't bond to a hook-and-loop face. The two mounts are not interchangeable.
Neither system is locked to one trade. You'll find both Hookit and Stikit discs running side by side in the same shop, sometimes on the same job.
- Auto body and paint prep: techs feathering out a repair or prepping a panel for primer often reach for Stikit's flat contact, then switch to Hookit for fast grit changes while blending a repair into clear coat.
- Woodworking and cabinetry: Hookit is common here since edges, profiles, and grit progressions favor quick, tool-free disc swaps.
- Metal fabrication: shops cleaning up welds or deburring on a stationary or air-powered disc sander often reach for Stikit's lower per-disc cost on long single-grit runs.
- General contracting: switching tasks throughout the day, from drywall patches to trim, usually favors Hookit's quick-change convenience over Stikit's long single-grit setup.
Setting Up Each System on Your Sander
For Hookit, the backup pad matters as much as the disc itself. A standard hook-faced pad works for most flat work. If you're sanding curves, contours, or body lines, an interface pad like the 3M 28323 adds a thin layer of foam between the backup pad and the disc. That extra give helps the disc follow the shape of the work instead of digging in at the edges. Match the pad's hole pattern to your sander's dust port. A mismatched pattern chokes off suction even if the disc mounts just fine.
For Stikit, the setup depends on whether you're running individual discs or sheet stock off a roll. Individual PSA discs peel and press directly onto a smooth pad, no extra hardware needed. If you're burning through a lot of one grit, a roll dispenser like the 3M 05452 holds two rolls of sheet material and lets you tear off a fresh piece as you go, which is a common setup on bench sanders and production lines.
One more thing worth knowing: dust extraction holes only help if they line up with the holes in your backup pad. Higher hole counts generally pull more dust off the work, and a mismatched hole pattern between the disc and the pad chokes off that airflow, which lets the disc load up and clog faster. Check your sander's pad spec, not just the disc's size, before you order a punched disc in either system.
It's also worth confirming the grit standard on the disc itself. Most discs are marked with a P grade, like P120 or P220, which follows an international grading scale. Some older or specialty discs still use the North American CAMI number instead. The two scales track closely through the coarser grits but start to drift apart in the finer range, so if you're matching a grit across brands or across a Hookit-to-Stikit swap on the same job, read the actual grade printed on the disc rather than assuming a number means the same thing everywhere.
One field tip worth stealing from other pros: hook-and-loop discs like Hookit hold up to reuse, but the printed grit number wears off fast once the loops start scrubbing against it. Family Handyman recommends marking the grit on the back of the disc yourself: "Hook-and-loop sanding discs work great for sanding jobs, and you can reuse them several times before they're worn out. But it's almost impossible to read the grit labels on the discs after you've used them once because the markings get scrubbed off by the loops. So mark them with a Sharpie on the backside of the disks to make a permanent reminder."
Key Takeaways
- Hookit uses hook-and-loop backing for tool-free, reusable disc changes in seconds.
- Stikit uses pressure-sensitive adhesive for a flatter, more rigid contact and a lower price per disc, but it's single-use.
- The two mounts aren't interchangeable. A Hookit disc won't grip a PSA pad, and a Stikit disc won't bond to a hook-and-loop face.
- Match the system to the job: frequent grit changes and curves favor Hookit, flat panels and long single-grit runs favor Stikit.
- Dust extraction only works if the disc's hole pattern matches the pad's hole pattern, regardless of which system you're running.
Frequently Asked Questions
What does Hookit mean on a 3M sanding disc?
Hookit is 3M's name for its hook-and-loop attachment system. The disc has a loop-fabric back that grips the hooks on a backup pad, similar to how Velcro works. It's built for quick disc changes and reuse.
What does Stikit mean on a 3M sanding disc?
Stikit is 3M's pressure-sensitive adhesive system. The disc has an adhesive backing under a paper liner. Peel the liner and press the disc onto a smooth, hard pad and it bonds on contact. It's a single-use mount.
Can I use a Hookit disc on a Stikit backup pad?
No. A Hookit disc's loop fabric won't grip a smooth PSA pad, and a Stikit disc's adhesive won't bond to a fuzzy hook-and-loop face. The two mounts aren't interchangeable, so match the disc to the pad you have.
Can you reuse a Stikit disc after taking it off?
Not reliably. Once you peel a Stikit disc off the pad, dust and debris get into the adhesive layer and it won't hold a second bond the way it did new. Most shops treat Stikit discs as single-use.
Which is better for auto body filler, Hookit or Stikit?
Many auto body techs lean toward Stikit for flat filler and panel work because the disc sits flat and rigid against a hard pad, which resists rounding the edges of the repair. Hookit still works fine here. It just has a touch more give from the pad underneath.
Do Hookit and Stikit discs come in the same grits and sizes?
Yes, for the most part. Both systems are available across common sizes like 3, 5, and 6 inch, and across similar grit ranges on paper, film, and cloth backings. The mounting method is the difference, not the abrasive itself.
Why do the holes on my sanding disc matter?
The holes let dust get pulled through the disc and pad into your sander's vacuum port. If the hole pattern on the disc doesn't match the pattern on your pad, dust extraction drops off and the disc clogs faster, even though it still mounts just fine.
Can I convert a pad from one system to the other?
Some backup pads and accessories are built with one face for hook-and-loop and the other for PSA, which lets a single pad run either disc type. Check the pad's spec before assuming it works both ways, since most standard pads are built for one system only.
Is one system more aggressive than the other?
Not because of the mount itself. How aggressively a disc cuts comes down to the grit, the grain type, and the backing material, not whether it's Hookit or Stikit. You can find coarse and fine options in both systems.