PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

12BTester,material Hardness

Sun Tec Corp · NSN 6635-00-663-4576 · FSC 6635 · No Item Name Available
Verified by PartsTable
NSN 6635-00-663-4576 — this item is cataloged by the U.S. Government under National Stock Number 6635-00-663-4576. Primary manufacturer part number: 12B.
Features
  • Tester,material Hardness — FSC 6635
  • Type/model Designation: OUR
  • Relationship to Similar Equipment: OUR IS REGULAR MODEL; OUS SUPERFICIAL MODEL 6635-00-509-5238 MAKES SMALLER INDENTATIONS
  • Indicator Reading Type: MULTIPLE
  • Vertical Capacity: 12.000 INCHES IN
  • Indicator Type: CIRCULAR DIAL
  • Installation Design: BENCH
  • Test Type: ROCKWELL
Applications
  • Industrial maintenance and repair
  • Government and military logistics
  • Equipment overhaul and refurbishment
General Description

The Tester,material Hardness, cataloged under National Stock Number 6635-00-663-4576, is classified within Federal Supply Class 6635 (No Item Name Available) of the Instruments and Laboratory Equipment group. The primary manufacturer of record is Sun Tec Corp. Government technical data includes 17 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 5 commercial cross-references from 4 manufacturers, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN6635-00-663-4576
Primary Part Number12B
Item NameTester,material Hardness
FSC / FSG6635 / 66 — No Item Name Available
ManufacturerSun Tec Corp
StatusCANCELLED
Type/model DesignationOUR
Relationship to Similar EquipmentOUR IS REGULAR MODEL; OUS SUPERFICIAL MODEL 6635-00-509-5238 MAKES SMALLER INDENTATIONS
Indicator Reading TypeMULTIPLE
Vertical Capacity12.000 INCHES IN
Indicator TypeCIRCULAR DIAL
Installation DesignBENCH
Test TypeROCKWELL
Functional ClassificationAA-8.6
Unpackaged Unit Weight100.000 POUNDS LBS
Indicator DesignCONVERSION CHART
Usage DesignEXTERNAL
Functional DescriptionBALL-CHECK DETERMINES HARDNESS OF RELATIVELY SOFT MATL; SPHERE-CONICAL DIAMOND PENETRATOR (BRALE) TESTS HARDER MATL SUCH AS TOOL OR SPRING STEEL; MEAS DP PENETRATION OF BALL OR BRALE CHECK; READINGS REFER TO RELATIONSHIP TABLE FOR TS OF MATL
Entry Date70-08-15
Accessory Components and QuantityANVIL,FLAT,APPROXIMATELY 2.500 IN. DIA 1; ANVIL,RAISED SPOT 1; ANVIL,RAISED V,FOR SMALL DIA WORK 1; ANVIL,V,FOR 0.250 IN. TO 5.000 IN. DIA STOCK 1; CHUCK,0.062 IN. STEEL BALL PENETRATOR W/50 BALLS 1; COVER,TELESCOPIC ELEVATING SCREW 1; COVER,VINYL PLASTIC 1; PENETRATOR,DIAMOND C SCALE 1; WEIGHTS,FOR APPLYING 60 KG,100 KG,150 KG MAJOR LOADS 1 SET; TABLE,TESTING,8 IN. DIA 1; TEST BLOCKS FOR B SCALE 2; TEST BLOCKS FOR C SCALE 2 KG
Reference Data and LiteratureTM 55-405-10 AND ROCKWELL HARDNESS TESTER BOOK
Carrying CaseNOT PROVIDED
Horizontal Reach5.500 INCHES IN
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 12
3441-00-009-2848 INTERCHANGEABLE
Forming Machine,sheet Metal,slip
3110-00-156-1750 INTERCHANGEABLE
Bearing,ball,thrust
5935-00-192-4789 INTERCHANGEABLE
Jack,telephone
5905-00-283-3927 INTERCHANGEABLE
Resistor,current Regulating
6625-00-445-6930 INTERCHANGEABLE
Test Set,telephone
6240-00-469-624212B INTERCHANGEABLE
Lamp,incandescent
General Dynamics Mission Systems, Inc.
5315-00-482-1479 INTERCHANGEABLE
Pin,straight,headless
5935-00-539-119212B INTERCHANGEABLE
Jack,telephone
Switchcraft Inc.
5307-00-627-3446 INTERCHANGEABLE
Stud,plain
6625-00-649-4929 INTERCHANGEABLE
Lead,test
Cross-Reference Index
Part NumberManufacturer
12B PRIMARY Sun Tec Corp (USA)
12B Service Diamond Tool Company Dba Service Physical Testers Div Div Service Physical Testers (USA)
4OUR Page-Wilson Corp Measurement Systems (USA)
C12A The Clark-Eliance Corp (USA)
4-OUR Page-Wilson Corp Measurement Systems (USA)
Related Parts
3441-00-009-2848INTERCHANGEABLE
FORMING MACHINE,SHEET METAL,SLIP
3110-00-156-1750INTERCHANGEABLE
BEARING,BALL,THRUST
5935-00-192-4789INTERCHANGEABLE
JACK,TELEPHONE
5905-00-283-3927INTERCHANGEABLE
RESISTOR,CURRENT REGULATING
6625-00-445-6930INTERCHANGEABLE
TEST SET,TELEPHONE
6240-00-469-6242INTERCHANGEABLE
LAMP,INCANDESCENT
12B
5315-00-482-1479INTERCHANGEABLE
PIN,STRAIGHT,HEADLESS
5935-00-539-1192INTERCHANGEABLE
JACK,TELEPHONE
12B
5307-00-627-3446INTERCHANGEABLE
STUD,PLAIN
6625-00-649-4929INTERCHANGEABLE
LEAD,TEST
4730-00-781-9629INTERCHANGEABLE
COUPLING HALF,QUICK DISCONNECT
H4S/S
5945-00-815-8628INTERCHANGEABLE
RELAY,ELECTROMAGNETIC
C12A

Frequently Asked Questions

What is NSN 6635-00-663-4576?

NSN 6635-00-663-4576 is a Tester,material Hardness, manufactured by Sun Tec Corp, classified under FSC 6635 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 6635-00-663-4576?

NSN 6635-00-663-4576 has 5 cross-referenced part numbers: 12B (Sun Tec Corp), 12B (Service Diamond Tool Company Dba Service Physical Testers Div Div Service Physical Testers), 4OUR (Page-Wilson Corp Measurement Systems), C12A (The Clark-Eliance Corp), 4-OUR (Page-Wilson Corp Measurement Systems).

What NSN replaces 6635-00-663-4576?

There are 12 known substitutes for 6635-00-663-4576: 3441-00-009-2848, 3110-00-156-1750, 5935-00-192-4789 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 12B?

Key specifications for 12B: Type/model Designation: OUR; Relationship to Similar Equipment: OUR IS REGULAR MODEL; OUS SUPERFICIAL MODEL 6635-00-509-5238 MAKES SMALLER INDENTATIONS; Indicator Reading Type: MULTIPLE; Vertical Capacity: 12.000 INCHES IN. 17 total characteristics are documented in the Federal Logistics Information System.

Is NSN 6635-00-663-4576 still in active supply?

NSN 6635-00-663-4576 is currently cancelled. Check with the Defense Logistics Agency for current availability and authorized substitutes.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
PartsTable Design LLC · partstable.com