In the world of mechanical assembly and maintenance, these two screwdriver types remain the most fundamental:
When a manual specifies using only these two tools, it typically implies a "tool-free" or "basic-tool" maintenance philosophy intended for the operator rather than a specialized technician. For example: 121 : Only a Slotted and a Crosshead Screwdrive...
: On equipment like the 6800 Series Single Column Table Model, page or section 121 details testing limit stops, a task requiring minimal tools to ensure the crosshead moves safely. In the world of mechanical assembly and maintenance,
: Often called a standard or flat-blade screwdriver, it features a single chisel-shaped tip designed to fit into a straight slot on a screw head. It is the oldest and simplest type of screw drive. It is the oldest and simplest type of screw drive
The phrase appears to be a direct instruction or requirement from a technical manual or assembly guide, likely for an Instron testing system. In such contexts, "121" often refers to a specific procedure or page, such as testing limit stops or general maintenance, where these two tools are the only ones required. The Two Essential Driving Tools