Product Description
Type - Serrated flange bolts/screwsThread - UNC (Imperial coarse thread)
Grade - Grade 5 High Tensile Steel (8.8 Metric equivalent)
Finish - Zinc Plated Steel
Sizes are listed as -
Thread size (diameter) x length (measured from under the head)
All sizes are serrated under the head.
1/4" is 20 threads per inch.
5/16" is 18 threads per inch
3/8" is 16 threads per inch