Tool Clamping Technology and Selection - Total Cost of Ownership (TCO)

Which tool clamping or tool holding system is your best overall value for your machining processes? When it comes to selecting the proper or the “best value” tool clamping system for your machining applications, you must first look at the type and size of cutting tools you want or need to use. The following factors will all have an impact on steering the decision for the most appropriate technology for your application: 1. Shank styles and sizes 2. Shank types – HSS/Tool Steel or Carbide 3. Material you will be machining and whether roughing, semi-roughing/semi-finishing, or finishing 4. Length of surface to be machines with regards to radial load on the cutting tool 5. Metal-removal rates – Aggressive or more “normal” 6. Spindle RPM capability and Spindle type – HSK, Steep-Taper, Steep-Taper with Face Contact, or Multi-tasking tapers like CAPTO® or KM®, and finally 7. Budgetary constraints – how much are you able or willing to spend for a tool clamping system With regards to the last item, it is important to recognize that cost of a tooling system is not the same as the Total Cost of Ownership (TCO). The often-overlooked component of the cost of the tool life lost due to excessive run-out can have a big impact on the long term financial calculations:

Total Cost of Ownership = Tooling System Cost + Tool Life Loss Selection

Tool Clamping System	Tool Holder Cost $	Cutting Tool Cost	Tool Life Loss (per cutting tool)	# of Cutting Tools Used	Total Cost of Ownership
CAT40 End Mill Holder	$100.00	$50.00	$30.00 (60% loss)	10 endmills	$900.00
CAT40 ER32 Holder	$180.00	$50.00	$20.00 (40% loss)	10 endmills	$880.00
CAT40 AccuMill™	$350.00	$50.00	$10.00 (20% loss)	10 endmills	$950.00*
CAT40 AccuGrip™	#220.00	$50.00	$5.00 (10% loss)	10 endmills	$770.00**

* Actual TCO is better due to improved metal removal and higher productivity rates

** TCo is lower, but the additional cost of the shrink-fit machine needs to be factored in

Example 1:

CAT40 End Mill Holder with Solid Carbide four flute ½” end mill: Tooling System Cost = $100.00 (holder) + $50.00 (end mill) = $150.00 Tool Life Loss = 0.6 (average TIR of 0.0006 = 60% reduction of tool life) x $50.00 = $30.00. Total Cost of Ownership = TSC + TLL = $150 + $30.00 = $180.00 This means you need to add an additional $30.00 to your total tooling cost to account for the reduced life you’ll get because of the run-out associated with a standard end mill holder.

Example 2:

CAT40 ER32 Collet Chuck with the same four-flute, ½” end mill: Tooling System Cost = $180.00 (holder) + $50.00 (endmill) = $230.00 Tool Life Loss = 0.4 (average TIR of 0.0004 = 40% reduction of tool life) x $50.00 = $20.00. Total Cost of Ownership = TSC + TLL = $230 + $20.00 = $250.00

The TCO concept becomes far more important when we consider a longer production run since the TLL will overshadow the initial TSC.

From these examples, we can see that the cost of a tool holder is only part of the total cost of ownership associated with a tool holding solution, therefore one must look at the total machining processes to determine which tool clamping system is the best value for each application. TIR of your tool clamping system will play a significant role minimizing the TCO. The following table summarizes how various tool holder clamping systems compare against each other