How Summer-Ready Fasteners Can Save Your Projects

On hot summer days, you can escape the heat by going for a swim or cooling off in an air conditioned building. Fasteners, obviously, don’t have these options. Every fastener must remain hard at work literally keeping things together - regardless of the heat, humidity or weather predicament. Yet, prolonged heat and UV exposure can increase wear, weaken structural connection and create safety risk on the job site. 

The good news? When you know the risks you can take proactive steps to prevent heat-related issues.

Here’s how to check for six consequences of heat exposure - and how to prevent them before they become problems.

ONE: Thermal Expansion and Contraction

The Problem: Metals expand in the heat and shrink as they cool. This loosens bolts and creates a misalignment of joints over time. Look for signs of corrosion, discoloration, warping or loosening. Pay particular attention to fasteners in areas of high-stress or exposed areas.

Prevention: Choose fasteners designed to tolerate movement (e.g. expansion joints or flexible couplings).

TWO: Loss of Clamping Force 

The Problem: Heat reduces torque retention, especially in load-bearing or vibration-prone areas. As metal heats up, it expands, which includes the fastener and the parts being joined. This causes the joint to “relax,” dropping torque values dramatically. 

Prevention: Re-torque critical fasteners before and during the hottest months. Use heat-rated threadlockers or lock washers to maintain hold, focusing on load-bearing bolts, machinery with vibration and outdoor assembling exposed to daily heat cycles. 

THREE: Metal Fatigue and Creep

The Problem: Prolonged heat exposure can cause metal to deform permanently or develop microscopic cracks. These failures are particularly dangerous because fasteners can look fine from the outside… until they break. Bolts may appear slightly bent or stretched and fasteners may loosen even after retorquing. 

Prevention: Choose heat-treated or alloyed fasteners (e.g. 316 stainless steel, Inconel). And avoid overtightening, which increases stress under expansion. Click HERE for Melfast’s alloy and Inconel fasteners.

FOUR: Accelerated Corrosion

The Problem: Oxidation speeds up under extreme heat and humidity, salt or chemical exposure, making bare or untreated steel particularly vulnerable. Untreated and improperly coated fasteners are most often affected. 

Prevention: Choose fasteners with protective coatings, such as zinc, ceramic, or galvanization). And be sure to store fasteners properly - in a dry, shaded and well-ventilated area, not sealed plastic bins that trap heat and moisture. Check out more storage tips HERE.

FIVE:  UV Degradation (Non-Metal Components)

The Problem: Not all fasteners are made entirely of metal. Washers, gaskets, and coatings made from plastic or rubber are more vulnerable to ultraviolet radiation from the sun. This makes them more likely to crack, fade, or lose strength. As a result, the stability of the joint may fail - even if the metal fastener itself is still in good shape.

Prevention: Use UV-stable materials like PTFE (Polytetrafluoroethylene) or EPDM (Ethylene Propylene Diene Monomer). PTFE resists UV rays, heat, chemicals and weather and doesn’t degrade, crack or become brittle in sunlight. EPDM is a synthetic rubber with superior ozone and UV resistance. So it stays strong and flexible over time.

Inspect these components regularly for signs of breakdown: Look for cracking or chalking on rubber parts, faded or brittle plastic or deformed or shrunken washers / gaskets. Also check for compromised seals around the fastener.

SIX: Seized Threads & Galling

The Problem: High heat increases metal-on-metal friction, especially in stainless steel fasteners, leading to galling. Galling refers to a form of cold welding when metal threads rub together under high pressure. This causes them to lock and fuse. Summer heat makes the problem more likely because heat expands and tightens thread tolerances and makes over-torquing more likely.

Prevention: Apply a nickel- or copper-based anti-seize lubricant on threads before installation. This reduces pressure and prevents surface welding under pressure. It’s particularly important for stainless steel on stainless steel, aluminum fasteners and load-bearing joints. 

If you’re feeling the heat this summer, keep in mind your fasteners are, too.  Take a proactive approach to keep them in good shape with these simple steps.