ISO 3294:2016规定了60°、90°和120°角（包括60°、90°和120°角）直柄埋头孔的尺寸。 对于切割直径在8 mm至25 mm范围内的埋头孔，本规范仅规定了公制单位的尺寸，这些尺寸被视为未来唯一的建议尺寸。 这些尺寸仅适用于由高速钢制成的工具。然而，如果生产方法允许，柄可以用合适的替代材料制造，例如碳钢。 除非另有说明，否则埋头孔是正确的- 手工切割。 莫氏锥柄埋头孔是ISO 3293的主题。

ISO 3294:2016 specifies the dimensions of parallel shank countersinks for angles 60°, 90° and 120° inclusive. It specifies dimensions in metric units only, these being regarded as the only recommended dimensions in the future, for countersinks with cutting diameters in the range 8 mm to 25 mm. The dimensions apply only to tools made from high-speed steel. However, if the method of production allows, the shanks may be manufactured from a suitable alternative material, such as a carbon steel. Unless otherwise indicated, the countersinks will be right-hand cutting. Morse taper shank countersinks are the subject of ISO 3293.