Carbide self-sharpening crowns SA-4

The carbide self-sharpening crown CA4 is made in accordance with GOST 11108-70. The crown is reinforced with hard alloy. Designed for core drilling mainly of low abrasive, monolithic, slightly fractured and intermittent rocks: sandstones, sand shales, coarse siltstones, porphyrites, gabbro, silicified limestones. Applicable materials: body - steel 45 GOST 8732-78, cutters hard alloy VK6 GOST 3882-67, solder - brass L63.

In CA4 type drill bits , a dual-core reinforcement scheme is used with a group consisting of four main and cutting tools of type VK 8 G5109 and one tool used as an additional cutting tool G5108 and installed in the washing hole. The incisors in the crown are located at a negative angle and are rotated around its axis by an angle of 15 degrees.