SPAX® PowerLags® T-Star Washer Head, Interior Construction Screws, Yellow Zinc

Choose SPAX T-Star Washer Head Interior Construction PowerLag Screws. The low-profile, large-diameter design provides outstanding clamping force and improved aesthetics. Deep T-Star drive offers excellent bit engagement without requiring a “special” driver bit. Available in 1/4”, 5/16”, and 3/8” diameters and in lengths up to 10”. Yellow zinc coating for use in interior structural applications. Buy SPAX T-Star Washer Head PowerLags and interior construction screws in bulk pails or in job-friendly package quantities (hex driver included) from wholesalers, dealers, and specialty distributors or retail hardware and home improvement stores near you.

Base Part No.: 358102() or 458102()


SPAX PowerLags with built-on washer design is available in a variety of screw styles, including Hex head, T-Star, and multiple coating options. Our interior and exterior construction screws require no pre-drilling and drive faster and easier than conventional lags and other structural lag screws. We offer the largest selection of code-recognized structural wood-to-wood fasteners in the industry.

  • IRC / IBC Code Compliant DrJ TER No. 1912-07 Structural Fastener Properties
  • DrJ Technical Evaluation Report (TER No. 1802-03; Multi-Ply; Sawn lumber assemblies and engineered wood - LVL, PSL and LSL assemblies) 
  • Grade 5 durability
  • No pre-drilling required (1/4" and 5/16")
  • Patented thread serrations require up to 40% less driving torque to increase installation speed while helping prevent cracking in logs
  • Built-on washer head designs eliminate the need and extra cost of a separate washer 
  • Fastener length stamp on the head provides convenient identification without measuring and aids on-site inspections

Choose SPAX PowerLags structural wood to wood screws for interior and exterior applications. Request a sample pack of SPAX PowerLags today and build strong connections on the job site. Need something stronger? Shop our PowerLags collection designed for timber frame and log home construction.

For CAD documents, please see Technical Documents.

SizeDrive/Bit SizeThreadAvailable Pkg. Options
Retail PaxLarge Retail Pax1 lb. Box3 lb. Box5 lb. BoxIndividualProject PaxContractor PaxBulk Pail
1/4" x 2-1/2"T-30Partial1+1250500
1/4" x 3"T-30Partial1+1250500
1/4" x 3-1/2"T-30Partial1+1250500
1/4" x 4"T-30Partial1+1250500
1/4" x 4-1/2"T-30Partial1+1250500
1/4" x 5"T-30Partial1+1250500
1/4" x 6"T-30Partial1+1250500
5/16" x 3"T-40Partial1+1250250
5/16" x 3-1/2"T-40Partial1+50250
5/16" x 4"T-40Partial1+1250250
5/16" x 4-1/2"T-40Partial1+50250
5/16" x 5"T-40Partial1+
5/16" x 6"T-40Partial1+
3/8" x 5"T-50Partial1+25150
3/8" x 6"T-50Partial1+1225150
3/8" x 8"T-50Partial150
3/8" x 10"T-50Partial1+150
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