When the Tip Breaks: A 5-Step Emergency Checklist
This checklist is for anyone who's ever had a CNC machine stop mid-cycle because a turning insert or milling cutter tip shattered—and the client is expecting parts by tomorrow morning.
In my role coordinating rush tooling for a mid-size job shop, I've handled over 200 emergency orders in the past 5 years. These include same-day turnarounds for aerospace and automotive clients. My experience is based on orders ranging from $200 to $15,000. If you're working with large-scale production runs or ultra-precision medical parts, your experience might differ—but the principles here should still apply.
Here's the 5-step checklist I follow when a Sandvik Coromant tip breaks and I've got 36 hours to keep the line running.
Step 1: Stop, Assess, and Confirm the Exact Insert Grade and Geometry
The first reaction is panic. Don't. Step one is to confirm exactly what broke.
Check the tool holder. Then check the insert box or any legacy paperwork. Sandvik Coromant uses a standardized coding system (e.g., CNMG 120408-PM 4325). Write down the full code. If you can't read it, take a photo and send it to your supplier's technical support. Don't guess—ordering the wrong grade means a 24-hour delay, minimum.
Checkpoint: Before proceeding, confirm the following:
– Insert shape (e.g., CNMG, TNMG, WNMG)
– Chipbreaker designation (e.g., -PM, -MR, -MF)
– Grade number (e.g., 4325, 4425, 2025)
– Coating type if visible (e.g., CVD, PVD)
Step 2: Call Your Supplier—Don't Email
If you need a replacement in 24–48 hours, email won't cut it. Pick up the phone. Ask for the emergency sales desk. Most Sandvik Coromant distributors have a dedicated line for rush orders.
When I'm triaging a rush order, I always lead with: "I've got a machine down and a deadline in 36 hours. I need a [full insert code] express-shipped." Give them the exact code. They can check stock instantly. If they don't have it, ask for the closest substitute—but clarify the substitution. For example, a 4325 grade is a general-purpose CVD-coated grade for steel; a 4425 is a tougher version. Which one matters.
Oh, and I should mention: some suppliers mark up rush orders by 20–30% for same-day dispatch. That's normal. Factor it into your cost estimate.
Step 3: Ask About Machine Settings and Alternative Grades
While on the phone, ask: "What are the recommended cutting speeds and feeds for this grade in my application?" Most suppliers have technical data sheets (or they can look it up in Sandvik Coromant's online database). Get the recommended parameters before you install the new insert.
I once ordered a replacement insert without checking the specs. Installed it, ran the same program, and the tip broke within 15 minutes. The supplier's recommended feed rate was 20% lower than what we were using. That cost us an extra 3 hours of downtime. Don't make my mistake.
Checkpoint: Request the supplier's recommended cutting data for your material and operation. Note any adjustments to speed (SFM), feed (IPR), and depth of cut.
Step 4: Confirm Shipping Method and Track the Order
Normal lead time for a standard insert is 3–5 business days. For a rush, you need overnight or same-day air. Confirm the shipping method (e.g., FedEx Priority Overnight) and get a tracking number before you hang up.
I can't tell you how many times I've assumed "express" meant overnight, only to find out it's 2-day. One time, our supplier used a non-standard courier that didn't deliver to our industrial park until 5 PM. The client's deadline was 10 AM. We had to air-freight the insert from a different city at $800 extra.
If the supplier can't guarantee delivery by your deadline, ask if they have a local depot or if they can ship from a closer warehouse. Sandvik Coromant's global distribution network usually has regional hubs that can deliver same-day within 200 miles.
Step 5: Prepare the Machine and Operator for the New Insert
While waiting for the replacement, prep the machine. Clear the swarf. Check the tool holder seat for damage. If the tip broke due to vibration or improper clamping, the holder might need a clean-up.
When the new insert arrives, install it carefully. Follow the torque specs (don't overtighten—it can crack the carbide). Then run a test cut on a scrap piece. Adjust the program if the supplier recommended different speeds/feeds.
Checkpoint: Before production resumes, verify:
– Machine is properly cleaned and inspected
– Tool holder seat is free of debris
– New insert is seated correctly
– Program parameters match supplier recommendations
– Operator is aware of any changes
Common Mistakes to Avoid
Based on my own missteps and those I've seen in the shop:
- Assuming all inserts are in stock. They're not. Even Sandvik Coromant best-sellers like the 4325 grade can have stockouts. Always call.
- Ignoring the chipbreaker. The -PM (positive medium) chipbreaker is great for general turning, but if your application is a finishing pass with light depth of cut, you might need a -MF (medium finishing). The wrong chipbreaker can cause poor chip control and tip breakage.
- Not having a backup supplier. If your primary distributor is out of stock, you need a plan B. I maintain a list of 3 approved emergency vendors.
- Cutting corners on shipping. If the client's penalty clause is $5,000 per day, paying $150 for overnight shipping is a no-brainer.
Small doesn't mean unimportant. When I was starting out, the suppliers who treated my $200 emergency orders seriously are the ones I still call for $10,000 repeat business. Today's small rush might be tomorrow's steady production line.
As of February 2025, USPS Priority Mail Express starts at $28.75 for a flat-rate envelope (usps.com). But for tooling emergency orders, overnight couriers like FedEx or UPS are more reliable for delivering to industrial addresses by morning. Per FTC guidelines (ftc.gov), any claims about shipping times must be substantiated; your supplier should guarantee delivery windows.
