1/4 " npt thread uses 1/4" allan wrench. 1/4" npt has a nomial o.d. of 0.540" grade 6061t6 aluminum. Gold anodized aluminum. Tech302 6541150.
5x 3/8 NPT Pipe Plugs Male Thread Allen Socket Hex Countersunk Plugs block off
1/8" NPT Pipe Plugs Aluminum w/ allan head 12 per pkg Red anodized aluminum
1/8" NPT Pipe Plugs Aluminum w/ allan head 12 per pkg Blue anodized aluminum
1/4" NPT Pipe Plugs w/recessed allan head 12 per pkg Red anodized aluminum
1/4" NPT Pipe Plugs Alum w/ allan head 6 pack grade 6061t6Red anodized alum
Pack of 20. 1/2" NPT PIPE PLUGS ALLEN HEAD SS304