Universal External Tri-Roll Gages
Tri-Roll Variable Reading Thread Gages
ADJUSTABLE 3-POINT GAGE FRAME – Has a self-contained alignment system that eliminates the need for setting templates or micrometers to achieve perfect 120° spacing. The frame design re-duces the inspection space and additional expense normally required by other systems using numerous gage frames for different sizes.
GAGE RANGE – The 3-POINT™ Thread System covers a size range from #4 (3mm) to 1-1/2” (40mm) with two adjustable frames.
GAGE PERFORMANCE – The gage roll sets are easily changed from one size to another. The lower rolls are mounted in a fixed position to support the workpiece. The upper roll arm assembly exerts a consistent force and actuates the indicator providing ac-curate readings.
GAGE DURABILITY – Thread rolls are designed to revolve with the workpiece, distributing wear evenly. (OptionaL) TITANIUM-NI-TRIDE (TiN) coatings protects the gage roll surface and provides additional hardness that extends gage roll life.
SPC COMPATIBLE – Universal gages provide the ideal system for data collection. Adjustments can be made at the machine before scrap is created, resulting in improved productivity and quality.

External Tri-Rolls
- BEST WIRE ROLLS- Pitch Diameter (Minimum Material condition)
- FULL FORM ROLLS- Functional Diameter (Maximum Material condition)
- PLAIN ROLLS- Major Diameter (Multi lobe out-of- roundness)
- CONE & VEE ROLLS- Single Element Pitch Diameter Flank contact limited
- MINOR DIAMETER ROLLS- (55° included angle) Two full profile “vee” rolls and one full profile cone roll
GAGE TRI-ROLLS There are interchangeable gage rolls available for standard thread gaging
applications. Each set of 3 rolls corresponds to one particular thread size. For measuring Pitch Diameter
use best wire rolls. For measuring Functional Size use full form rolls. For measuring Major Diameter use
plain rolls. For measuring Minor Diameter (not shown) use included angle rolls. Special thread rolls are
priced on request.

External 2-Point Thread Gages
2-POINT THREAD GAGE– Utilizes the most advanced precision linear bearings system. Accurate linear movement and consistent gaging force assures repeatable readings throughout the measuring range. Universal’s 180° frame design provides the best method for gaging functional size and other thread geometry. Helical path seating and 60% peripheral contact provide functional size position within the pitch diameter tolerance assigned.
GAGE RANGE – The 2-POINT gages cover a size range from #4 (3mm) to 3/4” (20mm) or 13/16” (22mm) to 1-1/2” (40mm).
GAGE PERFORMANCE – The external thread gages are easily set-up to use. With an appropriate thread setting plug gage, adjustment can be made quickly in setting the indicator to the actual size of the master, greatly reducing inspection time.
GAGE DURABILITY – The external 2-POINTTM thread gages are constructed to provide a consistent
gaging force for repeatable readings. The frame offers positive alignment that gives the flexibility to measure parts at the machine.
UNAMBIGUOUS READINGS – A consistent and precise reading eliminates opinion and operator variability. With a master thread plug gage, setting adjustments are made in seconds allowing actual size to be “seen” as opposed to the operator “feel” necessary with GO NO/GO ring gaging.

External Segments
- BLADE SEGMENTS- Minor Diameter & Taper (Minimum Material Condition)
- FULL FORM SEGMENTS- Functional Diameter (Maximum Material Condition)
- FLAT SEGMENTS- Major Diameter (Multi Lobe Out-Of-Roundness)
GAGING SEGMENTS – There are various interchangeable gaging segments available for standard and special threads. Thread gage segments are (Optional) TITANIUM-NITRIDE (TiN) coated for maximum wear. This coating provides additional hardness to the surfaces and visual indication of the need for replacement. Special thread segments are priced on request.

Master Setting Thread Plug Gages
SETTING THREAD PLUG GAGES – Universal Master Setting Thread Gages provide a traceable means to set and maintain the Variable Reading Thread Gaging System. Each thread size requires a Master Setting Thread Gage to establish a calibrated position before measuring a product. These masters are certified To N.I.S.T standards.
