Question

chapter 3
fasteners, sealants, and gaskets

name maximo pinho
date ____________ period 5
instructor: olson

after studying this chapter, you will be able to:

• identify fasteners used on small gas engines and implements.
• remove and install various fasteners correctly.
• repair or produce internal and external threads.
• properly select and install fasteners.
• remove, select, and install gaskets correctly.

instructions: after studying chapter 3 of the text, complete the following questions and problems.

1. list at least four of the various conditions to which fasteners are exposed during service.

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1. a thread is a(n) ___ ___ that circles around a shaft, or in a hole.
2. ______
3. ______
4. ______

1. flat head screws or bolts must have their heads set into a(n) _____ hole so they will be flush with the surface.

1. the most common angle for the heads of flat head screws is _____.

Explanation:

Question 1

Fasteners in small gas engines and implements face various service conditions. Common ones include vibration (from engine operation), temperature changes (engine heat/cooling), moisture (leading to rust), and chemical exposure (from fuels/lubricants). Also, mechanical stress (from load) and dirt/debris exposure are typical. We pick four: vibration, temperature changes, moisture, chemical exposure.

A thread is a helical ridge (or "screw thread") that circles a shaft (external thread) or a hole (internal thread). The term for the thread's structure is a "helical ridge" or "screw thread", with "helical ridge" fitting the blank structure (two words).

Flat - head screws/bolts need their heads flush with the surface, so they go into a countersunk hole. A countersunk hole is tapered to let the flat head sit flush.

Answer:

Four conditions: Vibration (from engine operation), Temperature changes (heating/cooling), Moisture (causing rust), Chemical exposure (from fuels/lubricants).

Question 2