Standard English Sizes
- Inexpensive, efficient, permanent method of closing/sealing manufactured holes in castings and other processes.
- Hubbard (Welch Type) Expansion plugs are perfect for limited space (depth) hole closure applications.
- Less expensive than cupped style plugs.
- Require a counter bore for installation.
- We have the widest range of sizes available anywhere – from 1/8” diameter up to 5-3/4” diameter.
Expansion plugs with a ground edge are available for applications requiring an exceptional degree of holding power or leak resistance.We are the original patent holder and manufacturer of the Welch Expansion Plug since 1913.
- Steel: SAE1008/1010 low carbon steel: ASTM#A109 or A569 depending on gage.
- Aluminum: 1100H14 to ASTM#B209.
- Brass: ASTM#B36.
- Stainless Steel: ASTM#A313
* These are materials we stock in various thicknesses. It does not mean we have finished inventory of all plugs in each of these materials.
** Customer specific materials different than those listed above are commonly run.
- Steel: provided plain finish with a light oil. Expansion plugs can be provided with a wide range of coatings: mechanical zinc (processed in house), electro-zinc, black oxide.
- Aluminum: provided plain finish. Aluminum plugs are washed in a light mineral spirit in order to remove any solvents or residue.
- Stainless Steel: Provided plain finish. Stainless Steel plugs are washed in a light mineral spirit in order to remove any solvents or residue. Stainless plugs can be passivated.
- Brass: provided plain finish. Brass plugs are washed in a light mineral spirit in order to remove any solvents or residue.
Entering an RFQ:
Find the desired plug diameter from the list of part numbers below. Click on this part number and then enter the requested information from the choices provided – material type, material thickness, requested finish (for steel), and desired quantity. You will also have the opportunity to send us any special notes or requirements for our review.