The #9089 Square Penetration Gage is a precision inspection instrument designed to measure recess penetration depth for square type head screws manufactured to Robertson square drive standards.

Square recess systems, commonly known as Robertson drive, are widely used in construction, industrial manufacturing, and assembly applications requiring positive engagement and reduced cam-out.

Proper penetration depth is critical to ensure full driver engagement, consistent torque transmission, and reliable assembly performance.

The 9089 Series utilizes a dial indicator based measurement system to determine recess penetration depth relative to the fastener head surface.

Available drive sizes:

9089-00 – Size 00

9089-0 – Size 0

9089-1 – Size 1

9089-2 – Size 2

9089-3 – Size 3

9089-4 – Size 4

When ordering, specify:

• Inch dial indicator

• Metric dial indicator

• Optional SPC compatible digital indicator

The 9089 Series is ideal for:

• Fastener manufacturers

• Industrial assembly operations

• Construction hardware producers

• Quality inspection laboratories

• OEM production facilities

Gage probes are heat treated, thermally stabilized, and surface treated to maximize wear resistance and dimensional stability.

Long form calibration certificates provide dimensional verification and traceability to the National Institute of Standards and Technology, NIST.

The 9089 Series ensures accurate and repeatable square drive penetration inspection.