Simpson 4d 1 1 2" Shake and Shingle Siding Roofing Nail, 316 Stainless Steel PACK:1 Lb (394) 10 x 40mm parallel shank 10 x 40mm parallel shank with driving flat and adjustable screw length the parallel shank fits standard boring machine collets and chucks securely DCU234P305GR: 350 Pk includes 1 driver bit included extending the service life of shingle and shake installations The annular ring shank combined with Type 316 stainless steel makes this nail a reliable choice for exterior shake and shingle work where long term holding power in wet or salt air environments is critical plain smooth shank alternatives simply cannot match this withdrawal resistance over time