The No. 628 ¹/₄” nozzle is crimped on the end to form a thin opening approximately ¹/₃₂” (0.030″) x ⁷/₃₂” (0.215″) to deliver a thin cross section of hot melt adhesive. It is good for precise edge sealing work. Attaches to either Crain No. 203, No. 204, or No. 207 Glue Guns or others guns with standard size thread. Thread size: ⁷/₁₆” major diameter- 20 threads per inch. In operation, this nozzle and melted glue are very hot, up to 400ºF. Users should avoid contact and keep out of reach of children.