Threaded Zinc Inserts

Polylok's threaded septic tank inserts are precision die-cast of zinc alloy with excellent resistance to atmospheric conditions. These septic tank inserts are specifically suited for use in precast concrete elements and these septic tank inserts can be quickly and easily secured to the form. Polylok septic tank inserts are excellent for securing machinery and equipment, for suspending piping and supporting railing/poles.


  • Easy to install
  • Made of heavy duty zinc alloy
  • Rust proof & corrosion-free

Part Number

  • 30383-15T (1/4 x 1 1/4")
  • 30381-24T (3/8 x 1")
  • 3038-25T (3/8 x 1 3/8")
  • 30381-25T-OB (3/8 x 1 3/8" open bottom)
  • 30380-35T (1/2 x 1 1/2")
  • 30380-36T (1/2 x 2 7/8")
  • 30382-45T (5/8 x 1 11/16")
  • 30382-46T (5/8x 2 7/8")
  • 30384-55T (3/4 x 1 11/16)
  • 30384-56T (3/4 x 3")

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Goes Well With

Threaded Insert Locators

Threaded septic tank Inserts Locators are now available in five sizes! 1/4'', 3/8'', 1/2'', 5/8'' and 3/4''. Polylok’s new threaded septic tank inserts locator revolutionizes the installation of all plastic and metal septic tank inserts. Our inserts shear off when the casting is stripped, never leaving an exposed hole or exposed threads. Just thread the locator into the septic tank inserts, then tap the insert into the pre-drilled 3/8'' hole and that's it! The hole will self seal allowing you to drill as many holes as needed without compromising form integrity.

Patent No # 6,789,776

Mold Fastening Nails

Polylok solves the problem of anchoring attachments to your concrete forms. Our mold fastening nails allow you to simply anchor mold attachments quickly and for less cost than older, time consuming methods. Quickly attach accessories to your mold such as: pulling irons, block-outs, unistrut clips, hole formers and lighting panel couplings. Attachments can be anchored with precision every time with our mold fastening nails. Polylok’s mold fastening nails are the simplest, most economical way to anchor mold attachments. The hole will self seal allowing you to drill as many holes as needed without compromising the form integrity.