The BOSCH SR‑1686 (Part No. 2608003027) is sold as a 2‑blade set of 315 mm / 12″ high‑speed steel (HSS) hacksaw blades featuring 18 teeth per inch (TPI) in Bosch’s signature blue finish, designed for high-speed metal cutting in mild and alloy steels. Each blade uses Bosch’s bi-metal lamination process, pairing cobalt-reinforced HSS teeth with a more flexible alloy-steel body to maintain cutting speed from first cut to last, resist premature fracture, and extend overall blade life. The blister-pack combination weighs approximately 60 g in total (≈ 30 g per blade), and is cut‑length compatible with standard 300‑315 mm / 12‑in hacksaw frames such as SR‑1686 or SR‑1680, operating with any ½″ blade clamp. Since these are consumable accessory blades, Bosch does not extend its usual 1‑year professional warranty to this item; support is limited to seller returns and replacement policies. Ideal for clean cutting in electrical conduit, metal tubing, mild steel rods, copper cabling, trims, or plastic sheet—especially where quiet, low-budget manual cuts are preferred.