Last Revision: January 29, 2010

1. First Cut has a limited selection of options available for threaded holes. See Table 1 for the thread diameters and pitches supported by First Cut. All internal threads will be right handed. Left handed threads, and diameter and pitches not shown in the table cannot be produced with the First Cut Process at this time.

2. First Cut can produce threaded holes if the model is submitted in native Solidworks (.sldprt), ProE (.prt) or AutoCAD (.ipt and .dwg, 3D only) formats or as files from other CAD systems output in IGES (.igs), STEP (.stp), Parasolid (.x_t or .x_b), or ACIS (.sat) formats. First Cut cannot produce threaded holes from models submitted in stereolithography (.STL) formats.

3. Threaded holes are produced using thread mills and the regular First Cut process: 3-axis milling from up to six orthogonal sides. We therefore must be able to orient your part with holes parallel to the cardinal axes, and must also be able to mill your geometry with the part in the same orientation.

4.You must model the pilot hole for a threaded hole. First Cut finds candidate threaded holes by looking at your model. It looks for holes that fall in a specific diameter range and that are in an allowable orientation. Table 1 shows the minimum and maximum pilot hole diameters for each supported thread. Table 1 also shows the the 75% thread engagement pilot diameter for the hole. The actual pilot hole diameter will be the larger of your modeled hole diameter or the 75% hole diameter. Note: The SolidWorks hole wizard will, by default, model the 75% thread engagement pilot hole. Other CAD package threading assistants may or may not model pilot holes properly. You can always model the hole as a regular geometry feature.

Due to inconsistencies in the way CAD systems and interchange formats represent threads, First Cut does not attempt to extract thread data from the 3D model. First Cut’s processes operate from 3D CAD models and no attempt is made to read or interpret drawings.

5. You must model any desired chamfering or other lead-in treatments. Note: The SolidWorks hole wizard will model various types of leads-in. Other CAD package threading assistants may or may not model lead-in properly. You can always model the leads-in as regular geometry features.

6.We may thread a through hole from either side of the part. If the depth of the hole is deeper than our tools can reach, we will offer to thread both ends of the hole. It should be assumed these threads will NOT be continuous. Table 1 shows the maximum thread depth that can be milled from one side of a part. The Threaded Holes Maximum Reach page shows how we will thread through holes or blind holes that exceed the reach of our threading tools from one or both sides.

7. We may be unable to thread holes that are obstructed by other features on your part or that are obstructed by our fixturing. If a hole cannot be threaded, no thread options will be offered for that hole.

8. When your quote is returned, the ProtoView ^™ 3D display will show you which thread types are possible for each hole. You will have the option on a hole by hole basis to select different threads (where possible) or no threads. The “Previous” and “Next” buttons allow you to move from hole to hole.  The “Options” drop down menu lets you assign a thread family (or no threads) to all holes that are candidates for threading.  Clicking the “Save Current Selections” or “Continue” buttons will save your choices. View FirstQuote Demo.

9. For those unable to see the threaded hole view using ProtoView, a 3D PDF is included that shows the thread options available for each hole.  Thread selections for each numbered hole can be made in the FirstQuote; however, the 3D PDF is not interactive and the list in the 3D PDF will not update.

10. External threads must be modeled. They are implemented using our standard ball and flat end mills and will be cut at the same time the rest of your geometry is milled. The smallest external thread that produces reasonable results is roughly 1/2-13 (M12) and depends strongly on your personal definition of “reasonable.”

11. After an order is placed, an order confirmation will be emailed with the thread sizes you selected. Please review the order confirmation for accuracy.