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
20 Qs. 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 11, 2025

-> All the aspiring candidates who wish to sit for the online examination scheduled for 15th July 2025, can download the ALP CBAT Admit Card using the direct link provided in the article.  

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

-> Railway Recruitment Board activated the RRB ALP application form 2025 correction link, candidates can make the correction in the application form till 31st May 2025. 

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

-> Bihar Home Guard Result 2025 has been released on the official website.

-> 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

Hot Links: teen patti refer earn teen patti classic teen patti master teen patti live