In a brazing operation, which of the following is the commonly used flux?

This question was previously asked in
ALP CBT 2 Fitter Previous Paper: Held on 23 Jan 2019 Shift 3
View all RRB ALP Papers >
  1. Sulphuric acid
  2. Hydrochloric acid
  3. Diesel oil
  4. Borax

Answer (Detailed Solution Below)

Option 4 : Borax
Free
General Science for All Railway Exams Mock Test
2.2 Lakh Users
20 Questions 20 Marks 15 Mins

Detailed Solution

Download Solution PDF

Explanation:

  • Brazing is the joining of metals through the use of heat and a filler metal whose melting temperature is above 450°C but below the melting point of the metals being joined.
  • Brazing is welding process in which filler metal is heated and melted to form flux, which fills the gap between parts to be joined.
  • Fluxes used are combinations of borax, boric acid, chlorides, fluorides, tetra‐borates and other wetting agents.
  • A popular composition of flux is is 75% borax and 25% boric acid.
  • Any form of oxide on the surface of a metal when heated will prevent a uniform flow of the brazing metals.
  • For this reason, a flux is necessary to eliminate the oxide.
  • A flux is a chemical compound used in brazing operation to dissolve oxides which are formed on the surface of metal and filler rod.
  • In brazing operation, Borax is used as a flux.
Latest RRB ALP Updates

Last updated on Jul 15, 2025

-> The Railway Recruitment Board has scheduled the RRB ALP Computer-based exam for 15th July 2025. Candidates can check out the Exam schedule PDF in the article.

-> RRB has also postponed the examination of the RRB ALP CBAT Exam of Ranchi (Venue Code 33998 – iCube Digital Zone, Ranchi) due to some technical issues.

-> The Railway Recruitment Board (RRB) has released the official RRB ALP Notification 2025 to fill 9,970 Assistant Loco Pilot posts.

-> The official RRB ALP Recruitment 2025 provides an overview of the vacancy, exam date, selection process, eligibility criteria and many more.

->The candidates must have passed 10th with ITI or Diploma to be eligible for this post. 

->The RRB Assistant Loco Pilot selection process comprises CBT I, CBT II, Computer Based Aptitude Test (CBAT), Document Verification, and Medical Examination.

-> This year, lakhs of aspiring candidates will take part in the recruitment process for this opportunity in Indian Railways. 

-> Serious aspirants should prepare for the exam with RRB ALP Previous Year Papers.

-> Attempt RRB ALP GK & Reasoning Free Mock Tests and RRB ALP Current Affairs Free Mock Tests here

Get Free Access Now
Hot Links: teen patti joy vip teen patti apk teen patti king teen patti master teen patti master apk best