Choosing a compression spring often comes down to a single question: do you need one exact spring for a known repair, or a ready supply of sizes for different jobs? In fasteners, springs, and industrial hardware, this is the difference between the 305mm Compression Spring and the 390-Piece Assortment Kit. Both are compression springs, but they serve very different purposes.
Quick Verdict
If you need a dedicated replacement spring, the 305mm Compression Spring is the direct match. If you want a versatile set of small springs, the 390-Piece Assortment Kit is the more flexible choice.
Comparison at a Glance
| Aspect | 305mm Compression Spring | 390-Piece Assortment Kit |
|---|---|---|
| Price | USD 82.25 | USD 10.90 |
| Quantity | 1 spring | 390 springs |
| Length | 305mm fixed length | Free lengths 5-30mm across 28 sizes |
| Wire diameter | 0.3-5mm listed | 0.3-0.8mm |
| Material | 304 stainless steel | 304 stainless steel |
| Storage | Single unit | Compartmentalized case included |
Where Each Product Wins
The 305mm Compression Spring is the clear choice when you need a dedicated replacement spring. Its format is suited to larger applications such as tractors, vintage cars, and industrial equipment, as described in the listing.
The 390-Piece Assortment Kit wins on versatility: it covers many common small-spring jobs without needing to order individual pieces.
Product Notes
305mm Compression Spring Steel Wire 0.3-5 mm 304 Stainless Steel Pressure Spring
This listing offers one compression spring with a fixed 305mm length, made from 304 stainless steel. The price is USD 82.25, so it's an investment in a specific part rather than a bulk selection. The wire diameter range is listed as 0.3-5mm, and the description notes that other dimensions can be requested. It's a strong candidate if you are replacing a spring in a larger assembly-think agriculture, metal construction, or vintage car repair-where the length matters. The limitation is that you get only one spring, and if it doesn't match your size requirement, you'll need to go back to the drawing board. For a single, known need, it does the job.
390 Piece Compression Spring Assortment Kit 28 Sizes Small Steel Springs Set
At USD 10.90, this kit is the lower-priced option and gives you 390 springs in 28 different sizes. The set covers wire diameters from 0.3-0.8mm and free lengths from 5-30mm, which makes it suitable for small repairs in hobbies, household items, and automotive tasks. The springs are 304 stainless steel, and they come in a reusable compartmentalized case with labeled sections, so you can find the right size quickly. The trade-off is that all the springs are small-there's no 305mm option here-and the plain finish means they're functional rather than decorative. If you want a broad selection of small springs, this kit delivers.
Final Choice by Use Case
Choose the 305mm Compression Spring if you have a specific replacement need and prefer a dedicated unit. Choose the 390-Piece Assortment Kit if you want a range of small springs for everyday projects, repairs, and prototyping. The kit gives you more options, while the single spring provides the exact part you need when you don't want to settle for an assortment.
