No large ones, but (101) amazingly assorted small extension and compression  springs -- most, but not all, 1" to 2" long. You might even find a stray torsion spring! Assorted lengths, assorted widths, assorted finishes, a sorta handy bag of replacement parts to have around the house.

These Bulldog Hardware steel gate hinges are black and measure 4-1/2” tall. Outside plate is approx 3” square with a slight taper and (4) 1/4” bores. Inside plate is 4” long x 1-3/8” with (4) staggered 1/4” bores. Hinges swing 270 degrees for fully opened gates. You’re going to need at least two unless you're making a cat flap.

Is it spring? Well, it’s a spring. This steel extension spring is technically a “short throttle return spring” and measures 2-1/4" long x 7/16", but it will be just as happy returning anything else if your throttle is already back where it belongs.

You could fit all of these springs in the palm of your hand, but they're still mighty handy. Steel extension springs, 1/2" long x 3/8" dia with 5/16" ID loops at each end.

This small compression spring measures 1" dia x 1-1/8" tall and is made from 1/16" dia 316-type stainless steel, designed for marine or other aquatic applications. Go mount a bouncing turtle.

Your ordinary generic everyday plain old steel hinge measures 2" long x 1-1/2" wide when open with a 1/8" axle and mounting holes just a hair under 1/4". Comes with screws, as they will. Ordinary, yes, but necessary.

You get a pack of (2) plated steel extension springs, 1" long x 3/4" dia, made from 7/64" stock. Open 9/16" loops at each end. Rated for loads up to 10-1/2 lbs, which means they're perfect for DIY scales and exercise contraptions, keeping heavy doors and gates shut, and hammocks for lap dogs.

These steel compression springs are 3/4” long x 1/2” dia and made of 1/32” thick stock. Compressed right here in the US of A.