Which type of thread is used in screw jack?

This question was previously asked in
ALP CBT 2 Fitter Previous Paper: Held on 21 Jan 2019 Shift 1
View all RRB ALP Papers >
  1. Buttress
  2. Square
  3. Knuckle
  4. Acme

Answer (Detailed Solution Below)

Option 2 : Square
Free
General Science for All Railway Exams Mock Test
2.1 Lakh Users
20 Questions 20 Marks 15 Mins

Detailed Solution

Download Solution PDF

Concept:

Square and trapezoidal threads are the most commonly used threads.

Square thread: 

  • In this thread, the flanks are perpendicular to the axis of the thread.
  • This is used for transmitting motion or power.
  • Examples Fly presses, Screw jacks, vice handles, cross-slide and compound slides, etc.

Trapezoidal threads: 

  • These threads have a profile which is neither square nor V thread form and have a form of a trapezoid.
  • Different forms of trapezoidal threads are ACME thread, Buttress thread, Saw-tooth thread, Worm thread
    • ACME thread: It has an included angle of 29°. These are used in lathe lead screws.
    • Buttress Thread: In this thread, one flank is perpendicular to the axis of the thread and another flank is at 45°. These threads are used in power presses, carpentry vices, gun breeches, ratchets, etc.
    • Knuckle thread: The shape of the knuckle thread is not trapezoid, but it has a rounded shape. It has limited applications. It is used for valve spindles, railway carriage coupling, hose connections, etc.

Fitter 35 25Q Hindi - Final images Q8

Latest RRB ALP Updates

Last updated on Jun 11, 2025

-> The RRB NTPC Admit Card 2025 has been released on 1st June 2025 on the official website.

-> The UPSC Prelims Result 2025 and UPSC IFS Result 2025 has been released @upsc.gov.in

-> 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.

-> 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 gold download apk teen patti 3a teen patti win teen patti joy 51 bonus teen patti earning app