# How to Quote Custom Compression Springs From a Print > Source: https://netray.co/resources/how-to-quote-custom-compression-springs-from-a-print > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Knowledge Base ## Short answer How spring makers estimate a custom compression spring quote: wire length, weight, coiler setup, run rate, secondary ops and scrap, plus where AI helps. ## Category ai-automation ## Content **Intro:** To quote a custom compression spring, convert the print into wire length and weight, add coiler setup and run time at the machine's real springs-per-hour, add secondary operations (stress relief, grinding, shot peening, presetting, plating, load test), then apply scrap, packaging and margin by quantity break. Most of the time goes into reading the print and deciding which wire and which machine, not into arithmetic. This guide walks the estimate in the order a spring estimator actually works, shows a worked wire-weight example, and explains where a private AI assistant over your past jobs saves hours without touching your pricing judgment. **Sections:** #### Step 1: Read the Print Like a Spring Engineer **Body:** Start with the callouts that set cost: wire diameter and material (music wire ASTM A228, oil-tempered A229, stainless A313, chrome silicon A401, chrome vanadium A231), outside or inside diameter, free length, total or active coils, end type (closed and ground versus closed not ground), and the load-at-length or spring-rate requirement. Whether the print calls out loads or dimensions only changes the risk: a load-controlled spring may need coil count adjusted per lot and 100 percent load testing, while a dimension-controlled spring does not. Note finishes, special packaging, and any customer spec such as a PPAP request or a cert requirement, because each adds a line to the quote. **Bullets:** - Material and wire diameter drive both cost and which coiler can run it - Tight tolerances on free length or load push you toward grinding, presetting and tighter process control - Squareness, perpendicularity and ends are common hidden cost drivers - Index or spring index (mean diameter divided by wire diameter) below about 4 or above about 12 makes coiling harder and raises scrap #### Step 2: Wire Length, Weight and Material Cost **Body:** Wire length per spring is roughly pi times mean coil diameter times total coils, plus a little for ends. Take a spring with 0.062 inch wire, 0.50 inch outside diameter and 10 total coils: mean diameter is 0.438, so length is about 13.8 inches, and at 0.283 pounds per cubic inch for steel the wire weighs about 0.012 pounds per spring. Multiply by your cost per pound for that wire size and heat, then add a scrap factor for setup scrap and lot-start rejects. Short runs on expensive stainless or chrome silicon can be dominated by the minimum wire spool you must buy, so quote the spool purchase and any remainder risk explicitly when the order quantity is small. #### Step 3: Setup, Run Rate and Machine Selection **Body:** Choose the machine first, because cost per hour and speed depend on it: a high-speed CNC coiler for small wire, a heavier coiler for larger diameters, or a multi-axis wire-forming machine if the spring has formed ends or extension hooks. Setup time covers tooling changes, wire feed rollers, coiling points, and first-piece approval, and varies a lot between a repeat part with saved programs and a new part. Run rate should come from actual history on that machine and wire size, not catalog speed, because testing, trimming and tangling downtime depress real output. Estimators who track springs per hour by part family and material quote more accurately than those using a single shop-wide rate. #### Step 4: Secondary Operations and Outside Processing **Body:** Most compression springs go through stress relief after coiling, often in a conveyor or batch oven, and many need grinding of ends, presetting (also called scragging) to set the spring, shot peening for fatigue life, and plating or coating. Each has its own setup, batch minimum, and either an internal cost or an outside vendor quote. Zinc or other electroplated high-strength springs raise hydrogen embrittlement concerns that call for bake-out, which adds time and a record. Load testing every piece or a defined sample is a labor cost that estimators often underestimate. List each operation as its own line so the customer can see where a tolerance change would save money. **Bullets:** - Stress relief temperature and time by material - End grinding setup and cycle time per piece - Shot peen and plating through approved outside vendors with lead time - Packaging, labeling, and customer-specific certs #### Where AI Helps, and Where It Does Not **Body:** The slow part of spring quoting is not math, it is finding similar past jobs, remembering what the shop actually ran, and keeping quotes consistent across estimators. A private AI assistant running on your own hardware can read the incoming print or RFQ, pull comparable parts from your ERP (wire size, coils, machine, actual springs per hour, scrap), and draft a line-item quote for the estimator to approve. Nothing writes back without a human. It is not worth it if you quote a few dozen springs a month and one estimator remembers every job; a good spreadsheet is enough there. It pays off at higher RFQ volume or when estimator knowledge is concentrated in one or two people. **Cta:** If your spring quotes still start with someone searching old jobs by memory, Netray can show a draft quote grounded in your own ERP history and run entirely on your hardware. **Faq:** #### How do you calculate the wire needed for a compression spring? **Answer:** Wire length is about pi times the mean coil diameter times the total number of coils, plus allowance for ends. Multiply cross-sectional area of the wire by that length and by the material density (about 0.283 pounds per cubic inch for carbon and alloy steel) to get weight, then multiply by cost per pound and add scrap. #### What drives the cost of a custom spring the most? **Answer:** Quantity, wire material and size, and tolerances. Tight load tolerances add load testing and process control, ground ends add a secondary operation, and plating or shot peening add outside processing. Setup is spread across the lot, so small runs carry a high per-piece cost. #### Should I quote springs by the piece or by the lot? **Answer:** Quote per piece at several quantity breaks, with setup and minimum order stated separately. That lets the buyer see the effect of volume and lets you protect margin on short runs where setup and wire minimums dominate. ## Related Slugs - stamping-quote-estimating-software - ai-rfq-review-for-metal-stamping-suppliers - wire-harness-costing-copper-prices-margins - ai-quoting-aerospace-defense-manufacturers ## Search terms spring quote estimating, how to quote custom springs, compression spring cost estimate, spring manufacturer quoting software, wire length calculation spring, custom spring pricing --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json