The Saber Manufacturing resource library: our own tools and guides, plus links to the official engine, propeller and FAA documents builders need when setting up a prop installation. Factory documents link straight to the manufacturer so you always get the latest revision. Can’t find something? Call or text (817) 326-6293.
Jump to: Saber Tools & GuidesLycomingContinentalRotaxPropellersFAASuppliersQuick Reference
Saber Tools & Guides
🧮 Prop Bolt Calculator
Find the right prop bolt length for your fixed-pitch prop. Covers standard and heavy-duty Lycoming flanges.
📏 SAE Flange Guide
Identify your SAE #1, #2, #5, #6 or Rotax pattern by bolt size, bolt circle and lug diameter.
🔧 Installation Instructions
How to install Saber prop bolts, extensions and crush plates.
📘 Lycoming SI 1098Q Explained
Plain-English guide to propeller flange bushing locations and how to use the official document.
Lycoming
📄 SI 1098Q: Propeller Flange Bushing Location
Official bushing part numbers, sizes and locations for Lycoming direct-drive propeller flanges, with a measurement checklist.
🗂️ Lycoming Technical Publications
Lycoming’s official library of service bulletins, service instructions, service letters, operator manuals and parts catalogs. You can also sign up for update emails.
Continental
🗂️ Continental Technical Publications
Maintenance, overhaul, operator and installation manuals for Continental engines (C-65, C-85, C-90, O-200 and more), available through Continental’s publications partner.
Rotax
🗂️ Rotax Technical Documentation
Official BRP-Rotax library of manuals, service bulletins and service letters for 912, 914, 915 and 2-stroke engines. Free to download.
Propellers
🪵 Sensenich Support Documents
Installation instructions, application guides, spinner documents and STC paperwork for Sensenich wood, aluminum and composite props, including wood prop torque procedures.
⚙️ Hartzell Service Instruction Index
Index of Hartzell propeller service instructions.
🪶 Catto Propellers
Hand-built composite fixed-pitch props for RVs, STOL, racers and more. Contact Catto directly for installation details and hub thickness for your prop.
🌀 Prince Aircraft (P-Tip)
Wood and carbon fiber P-Tip fixed-pitch props. Carbon P-Tip hubs can be thinner than typical wood hubs, so confirm hub thickness before sizing bolts.
🪵 Performance Propellers
Handmade wood fixed-pitch props for experimental aircraft. Now part of Fairings-Etc., which is restarting production.
⚠️ Whirl Wind Alert Service Bulletin WW-ASB-61-001: GA-200L Hub Inspection
Whirl Wind has received reports of cracking around the bolt holes in GA-200L ground-adjustable hubs and of broken hub clamping bolts. The bulletin requires initial and recurring hub inspections, inspection of the spinner backing plate, and recurring replacement of hub hardware. If you run a GA-200L, read it and make sure you have the latest revision.
FAA
📕 AC 43.13-1B: Acceptable Methods, Techniques & Practices
The FAA’s standard reference for aircraft inspection and repair practices, including hardware, safety wiring and torque. Widely used by homebuilders.
Builder Suppliers
✈️ Fairings-Etc.
US-made parts for experimental aircraft: lightweight fiberglass and carbon fiber fairings (wheel pants, gear leg and intersection fairings), tailwheels, and safety equipment, including Crow harnesses. Now also the home of Performance Propeller handmade wood props.
Quick Reference
What SAE do I have?
Check your bolt size, bolt circle (center of one hole straight across to the center of the opposite hole) and drive lug diameter, then match them below.
| SAE | Bolt Size | Bolt Circle | Lug Diameter | Common Engines* |
|---|---|---|---|---|
| SAE #1 | 3/8″ | 4.375″ | .625″ | C-65, C-85, C-90, O-200, O-235 |
| SAE #2 | 3/8″ | 4.75″ | .625″ | O-235, O-290, O-300, O-320, O-340 |
| SAE #5 | 7/16″ | 4.75″ | .625″ | O-320, O-340 |
| SAE #6 | 1/2″ | 4.75″ | .75″ | O-340, O-360, C-375, O-540, O-720, 4-cyl C-360 |
| Rotax 912/914/915/916 | 8mm | 4″ (101.6mm) | .500″ | 912, 914, 915, 916 |
| Rotax 912 (pre-1997) | 8mm | 100mm | .500″ | Early 912 |
| Rotax 2-stroke | 8mm | 75mm | No lugs (1″ center bore) | 447, 503, 582 |
Crankshaft flange thickness
Used when figuring prop bolt length. O-320, O-360 and O-540 engines came with either a standard or heavy-duty flange, so measure yours at the bolt holes.
| Engine | Standard Flange | Heavy-Duty Flange | Drive Lug Head |
|---|---|---|---|
| O-200 | .25″ | – | .15″ |
| O-235 | .19″ | – | .20″ |
| O-320 | .27″ | .38″ | .20″ |
| O-360 / O-540 | .38″ | .44″ | .25″ |
| Rotax | .39″ | – | .15″ (if applicable) |
| ARP 502 | .32″ | .44″ | No lugs (dowels), uses nuts |
Engine and prop patterns can be different
Your engine flange and your propeller hub don’t always use the same bolt pattern. Our extensions can adapt between any two SAE patterns (Rotax pairs with SAE #1 only). Always check both the engine and the prop before ordering.
⚠️ Choosing the right diameter
- The extension and crush plate diameter must be the same as or larger than your propeller hub’s mounting diameter. A smaller diameter can cut into the prop hub like a cookie cutter, causing loss of bolt torque and catastrophic failure.
- Fixed-pitch props on SAE #2, #5 or #6 use the 7″ diameter.
- Ground-adjustable and constant-speed props normally use the 6″ diameter.
- Rotax extensions are 5″ diameter.
Prop bolt length basics
Add up everything the bolt passes through, then add .1″ so at least 3 threads stick out past the drive lug for full thread engagement, an aviation safety standard. Always round up to the next stock length, never down.
- Into the engine: washer (.063″) + crush plate + prop hub + spinner bulkhead(s) + flywheel (.25″) + crank flange + lug head + .1″
- Spinner bulkheads: 1 bulkhead is usually .09″; 2 bulkheads are usually .063″ each
- Through-bolted (non-threaded) setups need a second washer and a nut. Call us to size these.
Bolts included with our extensions
Every Saber prop extension includes a free set of 12H extension-to-engine mounting bolts, sized to your bolt pattern. All Saber extensions are built to work with your stock / OEM prop bolts on the prop side, so no new prop bolts are needed.
| Extension Length | Mounting Bolt Length |
|---|---|
| 1.25″ | 2″ |
| 1.5″ | 2.25″ |
| 1.75″ | 2.5″ |
| 2″ | 2.75″ |
| 2.25″ | 3″ |
| 2.5″ | 3.25″ |
| 2.75″ | 3.5″ |
| 3″ and longer (spool) | 2″ |
This information is a general guide for experimental aircraft builders. Always follow your engine, propeller and airframe manufacturer’s instructions.
Need something custom?
Different length, diameter or pattern? We make parts for Lycoming, Continental, Franklin, Rotax, ARP and more.