Technical Foundation
What Is a Spherical Washer?
A spherical washer set consists of two washers with mating spherical (concave and convex) contact surfaces — the convex washer's curved face nests into the concave washer's matching curved recess, allowing the pair to rock relative to each other around the bolt axis while each washer's outer face remains flat against its respective clamped surface. This compensates for angular misalignment between the bolt hole axis and the surface being clamped, which is common where a bolted connection joins parts that aren't perfectly parallel — sloped flanges, angled brackets, or structural connections with fabrication tolerance.
Without a spherical washer set, a bolt tightened against a non-parallel surface bends slightly to seat the nut and bolt head flat, inducing bending stress into the fastener that reduces its effective clamping capacity and fatigue life. The spherical pair absorbs the angular mismatch mechanically instead, so the bolt is loaded in pure tension as intended, which is why spherical washers are specified in structural steel connections and any bolted joint with a known or expected angular offset.
Prefer a quick quote?
Get Spherical Washers Pricing in Your Inbox
Skip the search — tell us the bolt size and required angular compensation and we will come back with pricing.
| Spec | What It Means | Why It Matters |
|---|---|---|
| Angular Compensation Range | Commonly up to 6-8 degrees per DIN 6319 | Sets the maximum surface angle mismatch the set can accommodate |
| Bolt Size | Matched to specific bolt/stud diameter | Must match the fastener's diameter for proper bearing and clearance |
| Material | Carbon steel (often case-hardened), stainless steel | Determines load capacity and corrosion resistance for the application |
| Standard | DIN 6319 (common reference standard) | Provides recognized dimensional and angular compensation specifications |
| Set Configuration | Sold as a matched concave/convex pair | Both washers must be used together — a single washer from the set doesn't function alone |
Shop Spherical Washers
Browse Spherical Washers Sub-Categories
Organised by size and material. Pick a sub-category, or describe your bolt diameter and misalignment angle and let ChatMRO match the washer set.
How it works
From Half-Remembered Part Number to PO, in Three Steps.
Ask
Type an MPN, paste a spec sheet, or describe the part in plain English. ChatMRO understands engineer-speak.
Compare
Side-by-side specs, cross-references, and equivalents from multiple sources — without the clutter of endless browser tabs.
Quote & Buy
Request a quote or add to cart. Volume discounts, VAT-aware pricing, and consolidated procurement — all in one place.
Applications
Where Spherical Washers Get Used
Spherical washers are specified anywhere a bolted joint's mating surfaces are not perfectly parallel to the fastener axis and inducing bending stress into the bolt must be avoided.
Structural Steel Connections
Spherical washer sets compensating for flange angle tolerance in bolted structural steel connections and base plates.
Heavy Equipment & Machine Frames
Spherical washers absorbing angular misalignment in bolted joints on fabricated equipment frames and mounting brackets.
Pipe Support & Hanger Systems
Spherical washer pairs used in pipe hanger and support bolting where the support angle isn't perpendicular to the bolt axis.
Bridge & Infrastructure Construction
Spherical washers specified in structural bolting where fabrication tolerance introduces surface angularity.
Wind Turbine & Renewable Energy Structures
Spherical washer sets used in tower and foundation bolted connections requiring angular load compensation.
Material Handling Equipment
Spherical washers in conveyor and rack structural bolting where frame angularity would otherwise bend the fastener under clamping load.
FAQ
Spherical Washers Questions, Answered
What happens if I bolt a joint with surface angularity without a spherical washer set?
The bolt itself will bend slightly to allow the nut and head to seat flat against the non-parallel surfaces, which induces bending stress into the fastener in addition to its intended tensile clamping load. This reduces the bolt's effective load capacity and fatigue life, and in severe cases or under cyclic loading can lead to premature fastener failure.
How much angular misalignment can a spherical washer set correct?
Compensation range depends on the specific washer set's design, but common structural spherical washer sets (per DIN 6319) accommodate roughly 6-8 degrees of angular mismatch between the bolt axis and the clamped surface. Check the specific product's rated compensation angle against your actual measured or expected surface angularity before specifying.
Do I need to buy the concave and convex washers separately, or are they matched sets?
Spherical washers are sold as matched concave/convex pairs and must be used together — the convex washer's curved face and the concave washer's matching curved seat are what allow the pair to rock and absorb angularity. A single washer from the set doesn't provide the angular compensation function on its own.
Can spherical washers be used with standard flat washers in the same joint?
Yes, in many designs a standard flat washer can be used between the spherical washer set and the nut or bolt head as an additional bearing surface, but this depends on the specific joint design and available stack height — check the application's engineering requirements rather than assuming an additional flat washer is always appropriate.
Why are spherical washers commonly specified in structural steel bolting standards?
Structural steel fabrication inherently carries some angular tolerance between mating flange or connection surfaces, and structural bolts are often tightened to a specified high preload — combining that preload with an unaddressed angular mismatch would induce significant bending stress into a critical structural fastener, so codes and engineering practice commonly specify spherical washers wherever surface angularity exceeds an acceptable threshold.
Keep browsing
Related Categories
Explore More
Find Your Next Part Now.
Describe a part number, spec or what it does.