Are Jonny Bolts and Closet Bolts the Same Thing? Yes—why

Are jonny bolts and closet bolts the same thing? Yes — they are two names for the exact same part: the pair of bolts that anchor a toilet to the flange on the floor. Plumbers in different regions simply picked up different labels for it, and both stuck.

That naming confusion causes real problems at the hardware store. You ask for one thing, the clerk hears another, and you walk out wondering if you bought the wrong part. You didn't. This guide clears up the terminology once and for all, then walks through bolt sizes, materials, installation steps, and the mistakes that crack toilet bases.

By the end, you'll know exactly what to buy, how long the bolts need to be, and how tight to crank them without splitting porcelain.

Are Jonny Bolts and Closet Bolts the Same Thing? The Short Answer

Jonny bolts and closet bolts are the same hardware. Both terms describe the two bolts — sometimes called toilet anchor bolts — that pass through the base of a toilet and thread into or hook into the closet flange set into the floor. The toilet sits on a wax ring, the bolts clamp the bowl down, and plastic caps hide the hardware afterward.

So why two names? It comes down to trade vocabulary. A closet is old plumbing slang for a water closet — the toilet itself — so the bolts holding the closet down became closet bolts. The name "jonny bolt" (also spelled Johnny bolt) grew out of the same slang family, and it's the term you'll hear more often from supply houses and plumbers in certain parts of the United States, while big-box stores and packaging almost always say closet bolts or flange bolts.

Functionally, there is zero difference. A bag labeled "closet bolts" and one labeled "jonny bolts" contain the same 1/4-inch or 5/16-inch threaded studs, washers, and nuts. If a plumber asks for jonny bolts at the counter and the supplier hands over closet bolts, nobody blinks. The terms are interchangeable in practice, and knowing that saves you a return trip and a second conversation about the same part.

What a Closet Bolt Actually Does

The job sounds simple — hold the toilet down — but the bolt does three separate things at once, and understanding them explains why installation details matter so much.

First, it clamps the bowl to the floor. The bolt threads into the closet flange, a fitting that either glues onto the end of a PVC pipe, screws to a cast iron elbow, or gets embedded in concrete. When you tighten the nut on top, the bowl presses down against the floor and the flange, locking everything in place.

Second, it compresses the wax ring. The wax ring sits between the toilet's horn (the outlet on the bottom of the bowl) and the flange opening. Proper bolt tension squeezes the wax just enough to form a watertight, airtight seal. Too loose and the toilet rocks, breaking the seal and letting sewer gas and water leak out. Too tight and you can crack the porcelain base — a common and expensive DIY outcome.

Third, it keeps the toilet from shifting. A toilet that rocks even a quarter inch will work the wax ring loose within weeks. The bolts stop lateral movement, which is why they must sit on both sides of the bowl rather than just one.

• Clamps the bowl to the flange and floor
• Compresses the wax ring to form the seal
• Prevents rocking that destroys the seal
• Provides a mounting point for the trim caps

Toilet Flange Bolt Names Explained: Johnny, Closet, and Flange Bolts

Walk into any plumbing aisle and you'll see three or four labels for what is functionally one product. Here's the breakdown so you can translate whatever term a store, a plumber, or an online listing throws at you.

Closet bolts is the dominant retail name in the United States. Manufacturers like Oatey, Fluidmaster, and Sioux Chief print it on packaging because it matches the term used in plumbing codes and installation manuals. If you order parts online, this is the search term that returns the widest selection. (See Also: Are Head Bolts From Seadoo 587 the Same as 657)

Jonny bolts (or Johnny bolts) is the trade-counter name. It's especially common among plumbers and supply house staff, and it traces back to the same water-closet slang that produced "john" as a word for toilet. Same part, different vocabulary.

Flange bolts or toilet flange bolts is the descriptive name — it tells you where the bolt attaches rather than what it holds down. You'll also see toilet mounting bolts, bowl-to-floor bolts, and occasionally closet bowl bolts on packaging. In the UK and Australia, similar hardware is often called pan bolts, since a toilet is a "pan" there.

The one term to be careful with is lag bolts. Some flanges are secured to the subfloor with lag screws, and a confused search can surface those instead. Lag screws fasten the flange itself; closet bolts fasten the toilet to the flange. Different jobs, different parts.

Types and Sizes of Toilet Mounting Bolts

Not all closet bolts are equal. The differences that matter are material, thread size, and head style. Standard thread sizes are 1/4-inch-20 (the most common) and 5/16-inch-18 (heavier duty, common on commercial and wall-hung installations). Lengths typically run 2-1/4 to 3-1/2 inches, and some kits include extra-long bolts for flanges set on thick tile floors.

Here's how the main types compare:

Most kits include the bolt pair, two washers, two nuts, and sometimes plastic retainer washers that keep the bolt from sliding in the flange slot. Buy a kit, not loose hardware — the included washers and retainer clips are easy to overlook and annoying to source separately.

How to Measure and Choose the Right Bolts

Picking the right set takes about five minutes and prevents the classic failure: bolts too short to grab, or so tall the caps won't sit flush. Work through these steps before you buy.

1. Check the flange slot width. Most closet flanges have oblong slots roughly 1/4 inch wide that accept 1/4-inch bolts. Some heavy-duty and commercial flanges use wider slots for 5/16-inch bolts. Slide a bolt from your old set into the slot, or measure the slot with calipers if the flange is new.
2. Measure the exposed bolt height. After removing the old caps, measure how much stud sticks above the nut. You want roughly 1/4 to 1/2 inch of thread showing above the nut when installed — enough to grip, not so much that the cap bottoms out.
3. Account for floor thickness. If your toilet sits on a thick tile floor with the flange below, add the tile height to your length calculation. When in doubt, buy extra-long bolts and cut them down with a hacksaw.
4. Match the head style to the flange. T-head bolts slide into open slots; round-head bolts with retainer washers drop into slotted flanges from above. If your flange is already screwed down and the slots are covered, you need the T-head or the drop-in style with a retainer.
5. Choose material for your environment. Brass is the safe default. Choose stainless if the bathroom stays humid or you're near saltwater. Avoid bare zinc-plated steel for anything you want to last decades.

One more check: confirm the bowl's base openings. Some toilet bases have narrow channels that only accept a specific bolt diameter, so if you're replacing a 5/16-inch bolt with 1/4-inch hardware, verify the washer still spans the opening in the porcelain.

Installing Closet Bolts Step by Step

Whether you're setting a new toilet or re-seating an old one, the sequence is the same. Total time for a first-timer: 45 to 90 minutes, most of it spent on the wax ring and cleanup.

1. Shut off and drain. Close the supply valve behind the toilet, flush to empty the tank, and sponge out the remaining bowl water. Disconnect the supply line at the valve or the tank fill fitting.
2. Remove the old toilet. Pull the caps, remove the nuts, and rock the bowl gently side to side to break the wax seal. Lift straight up and set it on an old towel.
3. Scrape the flange clean. Remove all old wax from the flange and the bottom of the horn. A plastic putty knife works without scratching. Check the flange for cracks while it's exposed.
4. Set the bolts. Slide the T-heads into the flange slots or drop them in with retainer washers, oriented so the threads face up and the bolts sit parallel, about the width of the bowl's base apart. Some plumbers add a dab of silicone under the retainer to hold them in place.
5. Set the wax ring and seat the toilet. Press a new wax ring onto the flange (or onto the horn — both methods work), then lower the bowl straight down so both bolts pass through the base openings. Sit on the toilet or press down firmly to compress the wax. Do not rock it side to side at this stage.
6. Tighten evenly. Hand-thread both nuts, then alternate tightening a half turn at a time — left, right, left, right. Snug them with a wrench until the toilet no longer rocks. There's no published torque spec for porcelain, so go by feel: firm, then a quarter turn more, never a full-force crank.
7. Trim and cap. If the studs sit too tall, cut them with a hacksaw (protect the porcelain with tape), then snap on the plastic caps. Reconnect the supply, turn the water on, and check for leaks around the base over the next day or two.

Materials, Coatings, and Durability: What the Numbers Mean

The hardware aisle doesn't explain why one bolt kit costs $3 and another costs $9, so here's what actually drives the difference.

Thread size matters more than people expect. The standard residential closet bolt is 1/4-inch-20 coarse thread. Commercial and wall-hung carriers often use 5/16-inch-18. The two are not interchangeable: a 5/16-inch bolt won't fit a 1/4-inch flange slot, and a 1/4-inch bolt in a wide slot can shift under load. If you're buying replacement bolts for an existing toilet, take the old bolt with you and hold the new one against it. (See Also: Are Head Bolts O Gm 3 0 Reusable)

Corrosion behavior differs by metal. Brass doesn't rust — it may darken or develop greenish patina, but it stays structurally sound, which is why it dominates this category. Stainless steel resists rust even better in wet environments, though mixing stainless bolts with galvanized or zinc-plated nuts can cause galvanic corrosion over many years, so keep the fastener metals matched. Zinc-plated steel is fine when new, but if the plating gets scratched during installation, rust can creep in within a few years in a damp bathroom — and a rusted-through bolt means the toilet is effectively unanchored.

Hardness is a trade-off. Harder steel bolts resist snapping under wrench force but can be harder to cut down to length. Brass cuts easily with a hacksaw but strips more readily if cross-threaded. For most homeowners, brass threaded by hand first, then finished with a wrench, hits the right balance of strength and workability.

Check the kit contents too: a retainer washer (the flat plastic disc that keeps the bolt from rotating or sliding in the flange slot) is the piece most often missing from generic hardware, and it's the piece that prevents the frustrating "spinning bolt" problem during tightening.

Common Mistakes to Avoid

Most toilet bolt failures trace back to a handful of repeatable errors. Skip these and your installation will outlast the wax ring's natural lifespan.

• Overtightening. Porcelain cracks under point pressure. The failure pattern is predictable: a hairline crack radiating from the base opening, usually discovered days later when water appears around the toilet. Tighten until snug and stable, then stop.
• Uneven tightening. Cinching one side fully before touching the other tilts the bowl and compresses the wax ring unevenly, which creates a slow leak on the loose side. Always alternate sides, a half turn at a time.
• Reusing old bolts. A bolt that has been in a damp flange for a decade may be corroded, and its threads may be damaged from the previous removal. New bolts cost a few dollars; a failed seal costs a re-install.
• Skipping the retainer washers. Without them, the bolt can spin in the flange slot or slide inward as you tighten, making it impossible to get the nut snug.
• Setting the bolts wrong side out. T-heads must sit with the flat against the flange slot so they can't rotate. If the head sits proud or crooked, the bowl won't seat flat.
• Reusing the wax ring. Wax deforms permanently once compressed. If the toilet comes up for any reason, the ring needs replacing — a $5 part versus a $50 problem.
• Ignoring flange height. A flange sitting below the finished floor (common after new tile) needs a flange extender or extra-thick wax ring, or no amount of bolt tension will seal it.

If a bolt snaps during tightening, don't panic — snap-off designs exist precisely because this happens. Extract the broken stud with vise grips or a screw extractor, then start again with fresh hardware.

Troubleshooting and Special Cases

Some situations go beyond a standard swap. Here's how to handle the ones that trip people up most.

The bolt spins and won't tighten. Either the retainer washer is missing or the T-head has slipped out of the slot. Lift the cap, check the head position, and if the flange slot is stripped, use a bolt with a wider retainer plate or a repair ring that gives the bolt fresh metal to bite.

The bolt is rusted and won't turn. Penetrating oil left for 15 minutes usually frees it. If the nut is fused, cut the stud between the nut and the porcelain with a mini hacksaw blade or an oscillating multi-tool — carefully, with tape on the surrounding porcelain.

The bolt broke off inside the flange. If a stub remains, grip it with vise grips and back it out. If it's flush or below the flange surface, a screw extractor (drill a pilot hole, then twist the extractor counterclockwise) is the standard fix. A flange repair ring with new integrated bolt slots is the fallback when extraction fails.

The flange sits below the floor. This happens after flooring upgrades. Use a flange extender or an extra-thick wax ring; some installers stack a standard ring with a wax-free gasket for very large gaps. The bolts then need extra length to reach through the raised hardware.

Concrete slab floors. The flange is often glued or bolted to the slab, and there's no wood underneath to re-anchor to. If the flange itself is loose, use a concrete-rated repair ring or expanding anchor rather than trying to screw into bare slab. (See Also: Are Hardened Bolts Safe to Use on Tractors)

In every case, the fix ends the same way: fresh bolts, even tension, and a new wax ring.

Common Questions About Jonny Bolts and Closet Bolts

Are Jonny Bolts and Closet Bolts the Same Size?

Yes. Since they're the same part, the sizes are identical: most are 1/4-inch-20 thread in lengths from 2-1/4 to 3-1/2 inches, with 5/16-inch versions for commercial and heavy-duty flanges. Whatever name is on the package, check the thread size against your flange slot and your old bolt before buying. A kit that includes washers, nuts, and retainer clips covers virtually every residential toilet.

What Size Bolts Hold a Toilet to the Floor?

The overwhelming standard is 1/4-inch-20 coarse thread, 2-1/4 inches long for typical installations. Commercial toilets, wall-hung carriers, and some older cast iron flanges use 5/16-inch-18. For tile floors where the flange sits low, 3-1/2-inch extra-long bolts give you the reach you need, and you can cut them down after the toilet is seated.

Can I Use Regular Hardware Store Bolts Instead of Closet Bolts?

Not recommended. A standard hex bolt lacks the T-head or retainer that locks it into the flange slot, so it will spin or shift as you tighten. Thread length and head geometry matter here. Purpose-made closet bolt kits cost only a few dollars and include the retainer washers and caps, so substituting generic bolts saves pennies and creates a real reliability problem.

How Tight Should Closet Bolts Be?

Snug, not cranked. Tighten alternating sides a half turn at a time until the toilet stops rocking, then add roughly a quarter turn. There is no official torque specification for porcelain bowls, and overtightening is the leading cause of cracked toilet bases. If the toilet still rocks after reasonable tightening, the problem is usually an uneven floor or a low flange — not insufficient bolt tension.

Why Does My Toilet Rock Even with Tight Bolts?

Rocking with tight bolts almost always means the toilet isn't sitting flat. Common causes: an uneven floor, a flange mounted below the finished floor, old wax residue under the base, or a warped bowl base. Fix it with plastic toilet shims under the low side, then re-compress with a fresh wax ring. Tightening harder just risks cracking the porcelain without solving the gap.

Do I Need to Replace Closet Bolts Every Time I Remove the Toilet?

You don't strictly have to if the bolts are brass or stainless and undamaged, but replacement is cheap insurance. Zinc-plated steel bolts that have sat in a damp flange for years are often corroded and may snap or strip during reinstallation. Since a fresh pair costs a few dollars and you're already replacing the wax ring, most plumbers put in new bolts as standard practice on every re-seat.

What Are Closet Bolts Made of, and Which Material Lasts Longest?

The three common materials are brass, stainless steel, and zinc-plated steel. Stainless offers the best corrosion resistance, especially in humid bathrooms, followed closely by solid brass, which never rusts though it may patina. Zinc-plated steel is the budget option and can rust within a few years if the coating is scratched. For a bathroom you don't want to revisit, brass or stainless matched with compatible nuts is the durable choice.

Final Thoughts

Are jonny bolts and closet bolts the same thing? Yes — they're two regional names for one part: the bolts that anchor a toilet to the closet flange on the floor. Buy whichever label your store carries; the hardware inside is identical.

What actually matters is getting the details right. Match the thread size (usually 1/4-inch-20) to your flange slot, choose brass or stainless for longevity, and buy a kit that includes retainer washers and caps.

During installation, alternate tightening between the two sides a half turn at a time and stop once the bowl stops rocking — overtightening is the number one cause of cracked toilet bases. Pair the bolts with a fresh wax ring every time the toilet comes up, and the connection will hold reliably for years.