S-MS 01Z Self-drilling HVAC fasteners Self-drilling chipless screw without washer (carbon steel) for HVAC applications
S-MD 01 Z Self-drilling metal screws Self-drilling screw (zinc-plated carbon steel) without washer for thin metal-to-metal fastenings (up to 3 mm)
S-MD 03 Z Self-drilling metal screws Self-drilling screw (zinc-plated carbon steel) without washer for medium-thick metal-to-metal fastenings (up to 6 mm)