Nomenclature

The name of the HDD rock dilling product is composed of: diameter specification, series code, IADC code, additional feature code and version number.

• Diameter Specification

  Tricone Bits & Lugs: Diameter is denoted in imperial units (Examples:8 1/2, 9 7/8, 12 1/4). Reamers: Diameter is denoted in metric or imperial units, prefixed with a connection thread code (Examples: NC31 300, 054FH 18,065FH 1050).

• Serial Code

  It consists of three letters, which represent the classification and basic characteristics of the product. The following table 1 shows the code principle of the tricone bits and trenchless bit:

  
  

  Products	Classification code	Bearing Features	Sealing feature
  Tricone bit	S—Universal Tricone Bits	G—Rolling bearing H—Journal bearing	A—O-ring rubber seal V—Flat rubber seal J—Metal seal
  	C—Tricone bit for trenchless pilot hole
  Trenchless bit	C

  
  

  As shown in Table 2 below, it is the code principle of the reamers

  
  

  Products	Company code	Product code	Sealing feature
  Reamer	S	K	A—O-ring rubber seal V—Flat rubber seal J—Metal seal

  
  

  Table2.Code principle of reamers

  
  

• IADC Classification Code

  It is composed of three digits, the first digit represents the type of bit cutting structure and formation hardness, the second digit is the formation classification number, and the third digit is the bearing and sealing feature code.

• The additional feature code

  Reflects the special structure of the products. The common additional feature codes are shown in the following table:

  
  

  Code	Additional feature
  C	Centre nozzle port
  G	Special enhancement of lug back
  L	Lug back centralizing
  T	Trimming insert
  X	Wedge-shaped insert
  Y	Conical insert

  For reamer products, we'’ ll use "-" and a number after the additional feature code to indicate the number of trenchless bit.

• Version Number

  It is represented by letters and numbers with specific meanings, and the numbers represent the number of improvements, among which -1, -2, -3 are added after the version number to distinguish the first, second, and third trenchless bit.