Daptemn Expandable Freeze Rubber Plugs Kit — 16PCS (8 Sizes) Neoprene Engine & Pipe Seal

Daptemn 16PCS expandable freeze rubber plugs are a complete neoprene-and-alloy repair kit with eight sizes that seal engine block and pipe openings quickly without welding.

If you need a fast, temporary or semi-permanent seal for coolant or oil passages, this kit supplies a range of expandable rubber plugs built to fit many common freeze-plug hole diameters. The set contains 16 plug assemblies—two of each size—made from neoprene rubber with alloy hardware that expands against the bore for a pressure-tight fit. Everything is organized in a clear plastic case so you can find the right size on the bench or in the toolbox.

How do these expandable rubber plugs stop leaks?

The plugs work by expanding a neoprene sleeve inside the hole and clamping it with an internal plate and carriage bolt. Tightening the hex nut pulls the steel plate up, compressing the rubber outward to create a seal against the hole wall. This mechanical expansion creates a reliable barrier for liquids and gases without adhesives, welding, or machining.

• Neoprene sleeve expands to match irregular or slightly worn bores.
• Alloy carriage bolt and plate provide even compression and corrosion resistance.
• O-ring improves sealing around the bolt assembly to reduce seepage.
• Two plugs per size allow for multiple repairs or backups.

Which sizes are included and what hole ranges do they cover?

The kit contains eight different diameters with two pieces each, covering hole sizes from about 3/4" to 1-3/4". Each size spans a small range so you can select the nearest fit and expand to form a tight seal. The range makes this kit useful for many automotive freeze-plug bores as well as general plumbing or fabrication tasks.

• 3/4" plugs: fit holes approx. 19–22 mm.
• 7/8" plugs: fit holes approx. 22–25 mm.
• 1" to 1-5/8" sizes: cover incremental ranges up to 41–44 mm.
• Two of each size provide redundancy or paired repairs.

What are the components and how durable are they?

Each assembly combines a molded neoprene rubber sleeve with a steel chassis, alloy carriage bolt, hex nut, steel compression plate and an O-ring. The neoprene delivers flexibility and chemical resistance while the metal parts give the structural strength needed to maintain compression under pressure. Properly installed plugs resist oil and coolant seepage and remain serviceable for maintenance or longer-term use.

• Neoprene rubber: elastic, smooth finish, resists oils and coolants.
• Alloy steel plate and carriage bolt: strong clamp force and corrosion resistance.
• O-ring: adds secondary sealing around the bolt shaft.
• Clear plastic storage box: protects parts and keeps sizes sorted.

Who is this for: The Daptemn 16PCS expandable freeze plug kit is aimed at mechanics, home garage DIYers, restorers and fabricators who need a fast, non-weld repair for engine block freeze plugs, pipe openings, or temporary service plugs. If you work on older engines, perform coolant system repairs, or need adaptable plugs for plumbing or prototype work, this kit gives a compact, organized selection of sizes and robust hardware to get jobs sealed quickly.