FED-STD-H28/23

SCREW-THREAD STANDARDS FOR FEDERAL SERVICES SECTION 23 CLASS 5 INTERFERENCE-FIT SCREW THREADS

Year: 1989

Abstract: This section provides the standards for general purpose Class 5 interference-fit screw threads of modified National thread form in the Coarse Series (NC) for sizes 0.250 through 1.500 inches. Also provided are Navy ship specifications for special application interference-fit threads.
Interference-fit threads are intended to develop sufficient breakloose torques to prevent loosening of externally threaded parts in service where other, less costly methods are not deemed satisfactory.
The following classes of screw threads included in this section are listed below. 
          NC-5 HF   Ferrous material external threads for driving in hard                     ferrous material with hardness greater than 160HB            NC-5 CSF  Ferrous material external threads for driving in copper                     alloy and soft ferrous material with hardness 160BB or                     less            NC-5 ONF  Ferrous material external threads for driving in                     non-ferrous materials other than copper alloys            NC-5 IF   All ferrous material internal threads            NC-5 INF  All non-ferrous material internal threads


          NC-5 HFM  Nickel-copper (Monel), nickel-copper-aluminum (K-Monel)                     and hard ferrous material external threads            NC-5 IFM  Nickel-copper (Monel), nickel-copper-aluminum (K-Monel)                     and all ferrous material internal threads


          NC-5 HFK   Nickel-copper-aluminum (K-Monel) external threads for                      driving in hard ferrous material with hardness greater                      than 160HB            NC-5 CSFK  Nickel-copper-aluminum (K-Monel) external threads for                      driving in copper alloy and soft ferrous material with                      hardness 160HB or less            NC-5 ONFK  Nickel-copper-aluminum (K-Monel) external threads for                      driving in non-ferrous material other than copper alloys            NC-5 HFS   Application similar to NC-5 HF            NC-5 CSFS  Application similar to NC-5 CSF            NC-5 ONFS  Application similar to NC-5-ONF            NC-5 IFS   Application similar to NC-5 IF            NC-5 INFS  Application similar to NC-5 INF


          NC-5 TENTATIVE  Hard steel external threads for driving in                           hard materials such as cast iron, steel and bronze            NC-5 ALTERNATE  Hard steel external threads for driving in                           hard materials such as cast iron, steel and bronze


The issues of the following documents in effect on the date of invitation for bids or request for proposal form a part of this standard to the extent specified herein. 
          Federal standards.                FED-STD-H28/1   Nomenclature, Definitions and Letter Symbols for                               Screw Threads                FED-STD-H28/6   Gages and Gaging for Unified Screw Threads-UN and                               UNR Thread Forms                FED-STD-H28/20  Inspection Methods for Acceptability of UN, UNR,                                UNJ, M and MJ Screw Threads


(Activities outside the Federal Government may obtain copies of Federal specifications, standards and commercial item descriptions as outlined under General Information in the Index of Federal Specifications, Standards and Commercial Item Descriptions. The Index, which includes cumulative bi-monthly supplements as issued, is for sale on a subscription basis by the Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402.
(Single copies of this standard and other Federal specifications, standards and commercial item descriptions required by activities outside the Federal Government for bidding purposes are available from the General Services Administration Specification Section, Room 6662, 7th and D Streets, S.W., Washington, DC 20407; telephone (202) 472-2205.)
(Federal Government activities may obtain copies of Federal standardization documents, and the Index of Federal Specifications, Standards, and Commercial Item Descriptions from established distribution points in their agencies.)
The following document forms a part of this standard to the extent specified herein. Unless a specific issue is identified, the issue in effect on date of invitation for bids or request for proposal shall apply. 
          American National Standards.                 ASME/ANSI B1.12-1987 - Class 5 Interference-Fit Thread


(Application for copies should be addressed to the American Society of Mechanical Engineers, United Engineering Center, 345 East 47th Street, New York, NY 10017-2330 or the American National Standards Institute, 1430 Broadway, New York, NY 10018-3308.)
  • Show Full MetaData
  • Statistics