Crest Diameter and Ovality Gages – MRP®

Thirty years ago, Gagemaker introduced the MRP® crest diameter and ovality gage which forever mrp-group2gifmrpgroup1changed the industry. Today, the MRP® series of gages is the industry standard worldwide. Whether you call it Crest Diameter, Root Diameter, or Ball PD, Pitch Diameter governs the strength of the actual thread assembly and ensures API dimensional measurement specs are met. (Check out the new carbon fiber MRP AIR.)

The Gagemaker MRP® crest diameter gages measure the internal and external pitch diameters of tapered threaded connections. Any slight variations in diameter or ovality are immediately detected with these precision gages granting you total control over your quality. These versatile gages easily adjust to measure thread diameters ranging from 1½” – 20”. The ability to inspect a range of diameters with one gage, eliminates the need for a room full of ring or plug gages.

MRP® Crest Diameter and Ovality Gages

This MRP® series of gages detect variations in crest diameter (or pitch diameter) by the use of a gage shoe that rests on the crest of the threads. Variation in diameter is detected by the indicator readout. All of these gages are API approved for use on tubing connections sized 1” – 4½”.

External/InternalRangeExternal RangeInternal RangeReachDescriptionModel
Internal1 - 2½”-1 - 2½”Internal Small Crest/Pitch Diameter gageMRP-202
External1½” - 4½”1 - 2½”-4.4”External Crest Diameter Gage, 4.4” ReachMRP-1001
Internal1½” - 4½”1½” - 4½”4.4”Internal Crest Diameter Gage, 4.4”MRP-1002
External/Internal1½” - 4½”1½” - 4½”1½” - 4½”4.4”External/Internal Crest Diameter Gage, 4.4” Reach, External Range 1½” - 4½”, Internal Range 1½” - 4½”MRP-1003
External/Internal1¾” – 4½”2⅜” – 4½” 4.4”Internal/External Pitch Diameter Gage for Two Step Seal. Upper and lower arms are .740” diameter. Upper arm has standard travel of .150”. Shipped with T125 pts.MRP-1012-TSS
External/Internal1¾” – 4½”2⅜” – 4½” 4.4”Internal/External Pitch Diameter Gage, Two Step Thread, w/ 1.030” Horseshoe standoff for front and rear measurements. Arms have .740” diameter. Upper arm has extended travel of .350”MRP-1012-TST

This MRP® series of gages detect variations in crest diameter (or pitch diameter) by the use of a gage shoe that rests on the crest of the threads. Variation in diameter is detected by the indicator readout. All of these gages are API approved for use on tubing connections sized 1” – 4½” and casing connections sized 2⅜” – 20”. To check out the new carbon fiber MRP AIR, go here.

External/InternalExternal RangeInternal RangeReachDescriptionModel
External2⅜” – 20”-4.4”External Crest Diameter Gage, 4.4” reachMRP-2001
External2⅜” – 20”-4.4”External Crest Diameter Gage, 4.4” Reach, Straight BlocksMRP-2001-S
External2⅜” – 20”-7” External Crest Diameter Gage, 7” reachMRP-2001-7
External2⅜” – 20”-10” External Crest Diameter Gage, 7” reachMRP-2001-10
Internal-2⅜” – 20”4¼”Internal Crest Diameter Gage, 4¼” reachMRP-2002
Internal-2⅜” – 20”4¼”Internal Crest Diameter Gage, 4¼” reach, Straight BlocksMRP-2002-S
Internal-3½” – 20”7” Internal Crest Diameter Gage, 7” reachMRP-2002-7
Internal-3½” – 20”10” Internal Crest Diameter Gage, 10” reachMRP-2002-10
External/Internal2⅜” – 20”3½” – 20”4¼”Internal/External Crest Diameter Gage, 4¼” reachMRP-2003
External/Internal2⅜” – 20”3½” – 20”4¼”External/Internal Crest Diameter Gage, 2⅜” – 20”, 4¼” reach, Straight BlocksMRP-2003-S
External/Internal2⅜” – 20”3½” – 20”7” External/Internal Crest Diameter Gage, 2⅜” – 20”, 7” reachMRP-2003-7
External/Internal2⅜” – 20”3½” – 20”10” External/Internal Crest Diameter Gage, 2⅜” – 20”, 10” reachMRP-2003-10

This MRP® series of gages detect variations in crest diameter (or pitch diameter) by the use of a gage shoe that rests on the crest of the threads. Variation in diameter is detected by the indicator readout. All of these gages are API approved for use on casing connections sized 8⅝” – 24”.

External/InternalExternal RangeInternal RangeReachDescriptionModel
Internal8⅝” – 24”-3⅜”External Crest Diameter Gage, 3⅜” reachMRP-3001
External-8⅝” – 24”3⅜”Internal Crest Diameter Gage, 3⅜” reachMRP-3002
External/Internal8⅝” – 24”8⅝” – 24”3⅜”Internal/External Crest Diameter Gage, 3⅜” reachMRP-3003
External/Internal20” – 36”20” – 36”3⅜”Internal/External Crest Diameter Gage, 3⅜” reachMRP-3004

This MRP® series of gages detect variations in crest diameter (or pitch diameter) by the use of a gage shoe that rests on the crest of the threads. Variation in diameter is detected by the indicator readout. All of these gages are approved for use on tubing and premium connections sized 1½” – 24”.

External/InternalExternal RangeInternal RangeReachDescriptionModel
External/Internal2⅞” – 4½”1½” – 4½” 3⅜”Solid Body External/Internal Crest Gage, 3⅜” ReachMRP-1500
External4½” – 9⅝”-4”Solid Body External Pitch Diameter Gage, 4” reachMRP-2511
External4½” – 9⅝”-7”Solid Body External Crest Diameter Gage, 7” reachMRP-2511-7
Internal-4½” – 9⅝”3⅜”Solid Body Internal Crest Diameter Gage, 3⅜” reachMRP-2512
Internal-2⅜” – 4½” 7”Solid Body Internal Crest Diameter Gage, 7” reachMRP-2512-7
External/Internal4½” – 9⅝”4½” – 9⅝”3⅜”Solid Body External/Internal Crest Diameter Gage, 3⅜” reachMRP-2513
External4½” – 13⅜”-4”Solid Body External Crest Diameter Gage, 4” reachMRP-2521
Internal-4½” – 13⅜”4”Solid Body Inernal Crest Diameter Gage, 4” reachMRP-2522
External/Internal4½” – 13⅜”4½” – 13⅜”4”Solid Body External/Internal Crest Diameter Gage, 4” reachMRP-2523
External8⅝” – 24”-4”Solid Body External Crest Diameter Gage, 6¼”” reachMRP-3501
Internal-8⅝” – 24”4”Solid Body Internal Crest Diameter Gage, 6¼”” reachMRP-3502
External/Internal8⅝” – 24”8⅝” – 24”6¼””Solid Body External/Internal Crest Diameter Gage, 6¼”” reachMRP-3503

MRP® Setting Standards

MRP® Rod Style Setting Standards

Box (Left) & Pin (Right) MRP® Rod Standards Rod style setting standards are designed to preset MRP® crest diameter gages for accurate inspection of API threaded connections. Each set of standards consists of two precision ground rods that are ground to lengths in accordance with API Specifications 5B. The rod sets are securely attached together and labeled with the connection size and serial number. The rods set the location of the thread shoe and the distance between shoes for accurate inspection of threaded connections.

MRP® Frame Style Setting Standards

Box (Back) & Pin (Front) MRP® Frame StandardsFrame style setting standards are designed to preset the MRP® crest diameter gages for accurate inspection of API threaded connections. These standards consist of a rigid, non-adjustable steel block precision machined to proper size to tolerances of ±.0003″. Round style standards, smaller than 2⅜”, are available as specials (contact us directly for more information).

Tubing Connections Rod & Frame Standards

Connection SizeRod Standard - BoxRod Standard - PinFrame Standard - BoxFrame Standard - Pin
2⅜” MRP5B-238EUE-BMRP5B-238EUE-PFSTD-238E-B2FSTD-238E-P2
2⅞” MRP5B-278EUE-BMRP5B-278EUE-PFSTD-278E-B2FSTD-278E-P2
3½”MRP5B-312EUE-BMRP5B-312EUE-PFSTD-312E-B2FSTD-312E-P2
4”MRP5B-4EUE-BMRP5B-4EUE-PFSTD-4E-B2FSTD-4E-P2
4½”MRP5B-412EUE-BMRP5B-412EUE-PFSTD-412E-B2FSTD-412E-P2

Connection SizeRod Standard - BoxRod Standard - PinFrame Standard - BoxFrame Standard - Pin
2⅜” MRP5B-238NUE-BMRP5B-238NUE-PFSTD-238N-B2FSTD-238N-P2
2⅞” MRP5B-278NUE-BMRP5B-278NUE-PFSTD-278N-B2FSTD-278N-P2
3½”MRP5B-312NUE-BMRP5B-312NUE-PFSTD-312N-B2FSTD-312N-P2
4”MRP5B-4NUE-BMRP5B-4NUE-PFSTD-4N-B2FSTD-4N-P2
4½”MRP5B-412NUE-BMRP5B-412NUE-PFSTD-412N-B2FSTD-412N-P2
Casing Connections Rod & Frame Standards

Connection SizeRod Standard - BoxRod Standard - PinFrame Standard - BoxFrame Standard - Pin
4½”MRP5B-412B-BMRP5B-412B-PFSTD-412B-B2FSTD-412B-P2
5” MRP5B-5B-BMRP5B-5B-PFSTD-5B-B2FSTD-5B-P2
5½”MRP5B-512B-BMRP5B-512B-PFSTD-512B-B2FSTD-512B-P2
6⅝”MRP5B-658B-BMRP5B-658B-PFSTD-658B-B2FSTD-658B-P2
7”MRP5B-7B-BMRP5B-7B-PFSTD-7B-B2FSTD-7B-P2
7⅝”MRP5B-758B-BMRP5B-758B-PFSTD-758B-B2FSTD-758B-P2
8⅝”MRP5B-858B-BMRP5B-858B-PFSTD-858B-B2FSTD-858B-P2
9⅝”MRP5B-958B-BMRP5B-958B-PFSTD-958B-B2FSTD-958B-P2
10¾”MRP5B-1034B-BMRP5B-1034B-PFSTD-1034B-B2FSTD-1034B-P2
11¾”MRP5B-1134B-BMRP5B-1134B-PFSTD-1134B-B2FSTD-1134B-P2
13⅜”MRP5B-1338B-BMRP5B-1338B-PFSTD-1338B-B2FSTD-1338B-P2
16”MRP5B-16B-BMRP5B-16B-PFSTD-16B-B2FSTD-16B-P2
18⅝”MRP5B-1858B-BMRP5B-1858B-PFSTD-1858B-B2FSTD-1858B-P2
20”MRP5B-20B-BMRP5B-20B-PFSTD-20B-B2FSTD-20B-P2

Connection SizeRod Standard - BoxRod Standard - PinFrame Standard - BoxFrame Standard - Pin
4½”MRP5B-412L-BMRP5B-412L-PFSTD-412L-B2FSTD-412L-P2
5” MRP5B-5L-BMRP5B-5L-PFSTD-5L-B2FSTD-5L-P2
5½”MRP5B-512L-BMRP5B-512L-PFSTD-512L-B2FSTD-512L-P2
6”MRP5B-6L-BMRP5B-6L-PFSTD-6L-B2FSTD-6L-P2
6⅝”MRP5B-658L-BMRP5B-658L-PFSTD-658L-B2FSTD-658L-P2
7”MRP5B-7L-BMRP5B-7L-PFSTD-7L-B2FSTD-7L-P2
7⅝”MRP5B-758L-BMRP5B-758L-PFSTD-758L-B2FSTD-758L-P2
8⅝”MRP5B-858L-BMRP5B-858L-PFSTD-858L-B2FSTD-858L-P2
9⅝”MRP5B-958L-B>P110 or MRP5B-958L-BMRP5B-958L-PFSTD-958L-B2>P110 or FSTD-958L-B2FSTD-958L-P2
20”MRP5B-20L-B>JK55 or MRP5B-20L-BMRP5B-20L-PFSTD-20L-B2>JK55 or FSTD-20L-B2FSTD-20L-P2

Connection SizeRod Standard - BoxRod Standard - PinFrame Standard - BoxFrame Standard - Pin
4½”– 9.50# MRP5B-412S-9-BMRP5B-412B-9-PFSTD-412B-9-B2FSTD-412B-9-P2
4½” – OtherMRP5B-412S-O-BMRP5B-412B-O-PFSTD-412B-O-B2FSTD-412B-O-P2
5” – 11.50# MRP5B-5S-BMRP5B-5S-PFSTD-5S-B2FSTD-5S-P2
5” – OtherMRP5B-5S-O-BMRP5B-5S-O-PFSTD-5S-O-B2FSTD-5S-O-P2
5½”MRP5B-512S-BMRP5B-512S-PFSTD-512S-B2FSTD-512S-P2
6⅝”MRP5B-658S-BMRP5B-658S-PFSTD-658S-B2FSTD-658S-P2
7” – 17.00# MRP5B-7S-17-BMRP5B-7S-17-PFSTD-7S-17-B2FSTD-7S-17-P2
7” – OtherMRP5B-7S-O-BMRP5B-7S-O-PFSTD-7S-O-B2FSTD-7S-O-P2
7⅝”MRP5B-758S-BMRP5B-758S-PFSTD-758S-B2FSTD-758S-P2
7⅝”MRP5B-758S-BMRP5B-758S-PFSTD-758S-B2FSTD-758S-P2
8⅝” - 24.00#MRP5B-858S-24-BMRP5B-858S-24-PFSTD-858S-24-B2FSTD-858S-24-P2
8⅝” - OtherMRP5B-858S-O-BMRP5B-858S-O-PFSTD-858S-O-B2FSTD-858S-O-P2
9⅝”MRP5B-958S-B>P110 or MRP5B-958S-BMRP5B-958S-PFSTD-958S-B2>P110 or FSTD-958S-B2FSTD-958S-P2
10¾” - 32.75#MRP5B-1034S-32-BMRP5B-1034S-32-PFSTD-1034S-32-B2FSTD-1034S-32-P2
10¾” - OtherMRP5B-1034S-O-B>P110 or MRP5B-1034S-O-BMRP5B-1034S-O-PFSTD-1034S-O-B2>P110 or FSTD-1034S-O-B2FSTD-1034S-O-P2
11¾”MRP5B-1134S-B>P110 or MR5BP-1134S-BMRP5B-1134S-PFSTD-1134S -B2>P110 or FSTD-1134S-B2FSTD-1134S-P2
13⅜”MRP5B-1338S-B>P110 or MRP5B-1338S-BMRP5B-1338S-PFSTD-1338S-B2>P110 or FSTD-1338S-B2FSTD-1338S-P2
16”MRP5B-16S-BMRP5B-16S-PFSTD-16S-B2FSTD-16S-P2
18⅝”MRP5B-1858S-BMRP5B-1858S-PFSTD-1858S-B2FSTD-1858S-P2
20”MRP5B-20S-B>JK55 or MRP5B-20S-BMRP5B-20S-PFSTD-20S-B2>JK55 or FSTD-20S-B2FSTD-20S-P2

MRP® Gage Shoes, Accessories and Replacement Parts

Part TypeGageLengthDescriptionModel
ShoeMRP-202.500”External Thread Shoe, ½” long for MRP-202MRP-.500E
ShoeAll MRP® models.625”External Thread Shoe, ⅝” longMRP-.625E
ShoeAll MRP® models.625”Internal Thread Shoe, ⅝” longMRP-.625I
ShoeAll MRP® models.750”External Thread Shoe, ¾” longMRP-.750
ShoeAll MRP® models.875”Thread Shoe, ⅞” longMRP-.875
ShoeAll MRP® models1.000”Thread Shoe, 1.00” longMRP-1.00
ShoeAll MRP® models1.500”Thread Shoe, 1.50” longMRP-1.50
ShoeAll MRP® models2.250”Thread Shoe, 2.25” longMRP-2.25
ShoeAll MRP® models20 mmMetric Thread Shoe, 20 mm longMRP-20mm
Setting StandAll MRP® models-MRP® gage setting standMRP-GSS
Part TypeCorresponding Gage(s)ResolutionDescription
Block SetMRP-1000 SeriesMRP-1000 series block set for .375" armsMRP-10BL
Lower ArmMRP-1000 SeriesMRP-1000 series lower arm, .375" diameterMRP-10LA
Upper ArmMRP-1000 SeriesMRP-1000 series upper arm, .375" diameterMRP-10UA
KnobMRP-1000 SeriesMRP-1000 knob, shortMRP-10KB-S
Block SetMRP-1000 SeriesMRP-1000 series block set for 0.5” diameter armsMRP-10SBL
KnobMRP-1000 SeriesMRP-1000 knob, longMRP-10KB-L
Spring PlungerMRP-1000 SeriesMRP-1000 series spring plungerMRP-10SP
Wear Pad SetMRP-1000 SeriesMRP-1000 series wear pad setMRP-10WP
Lower ArmMRP-1000 SeriesMRP-1000 series lower arm, .5" diameterMRP-11LA
Upper ArmMRP-1000 SeriesMRP-1000 series upper arm for external/pin connections, .5" diameterMRP-11UA
Upper ArmMRP-1000 SeriesMRP-1000 series upper arm for internal/box connections, .5" diameterMRP-12UA
Block SetMRP-2000 SeriesMRP-2000 series block setMRP-20BL
Arm ClampMRP-2000 SeriesMRP-2000 series arm clampMRP-20BL
Spring PlungerMRP-2000 SeriesMRP-2000 series spring plungerMRP-20SP
KnobMRP-2000 SeriesMRP-2000 series knobMRP-20KB
Wear Pad SetMRP-2000 SeriesMRP-2000 wear pad setMRP-20WP
Wear Pad SetMRP-2000 SeriesMRP-2000 extended wear pad setMRP-20WPEX
RailMRP-2000 SeriesMRP-2000 series 12" cross railMRP-RAIL-12
RailMRP-2000 SeriesMRP-2000 series 18" cross railMRP-RAIL-18
RailMRP-2000 SeriesMRP-2000 series 24" cross railMRP-RAIL-24
Wear Pad SetMRP-3000 SeriesMRP-3000 wear pad setMRP-30WP
Wear Pad SetMRP-3000 SeriesMRP-3000 extended wear pad setMRP-30WPEX