1/4 in. x 6 in. Torx Powerlag T-Star Drive Washer Head Yellow Zinc Coated Lag Screw

A:  Hello, Please see engineering values below, values can be found on last page: https://spax.us/uploads/resources/PWLG-TSTAR-WH-YZ-Spec-pg.pdf

A:  Hello, We would recommend pre-drilling with 3/16 bit through the ply's but not into the main substrate, which is the 4x4 according to your description. Thanks for being a SPAX customer.

A:  Hal... I use Doug Fir every day. Drilling a pilot hole is a choice. I can tell you I drill pilot holes everyday. If I get a split because I I don't drill a pilot hole. I can tell you my customers don't even have to ask. Pilot holes mean a higher quality job. How you build your projects is how you BUILD YOUR REPUTATION. NUFF SAID. Tom in Lubbock, Texas

A:  definitly drill a pilot hole

A:  this is not a direct answer but I would take some scrap lumber and try several small bits- as well as these screws cut their own holes you will be surprised at how small a pilot you need vs regular lags

A:  T-30, I believe.

A:  Hello, The 1/4 x 6" T-Star washer head PowerLag uses a T-30 bit. Thank you for being a SPAX customer, The SPAX Team

A:  It tells you plainly on the box. T30

A:  This uses a T-30 T Star bit

A:  Description says T-30.

A:  t30

A:  T-30

A:  They offer a separate HCR (High Corrosion Resistance) version specifically for treated lumber and exterior use. You could use either one depending on your exact application and expected weather exposure.

A:  It's zinc plated, which is corrosion resistant.

A:  Yes, the screws can be used outside.

A:  Hello, We do not recommend a yellow zinc coated screw for exterior use. When using screws in an exterior application, we recommend a HCR or High Corrosion Resistant coating. In this case where you need a 1/4 x 6" screw we would recommend our HCR coated screw. These screws are available at Home Depot. If you are having trouble locating them, check with the Pro-Desk and reference SKU# 1001-653-754. Thank you for being a SPAX customer, The SPAX Team

A:  I was confused about this as well. The Facebook ad specifically shows an outdoor decking application, yet the specs on the Home Depot website indicate that they are for indoor use. I was considering them for my wooden truck flatbed top.