Composi-Lok II, Monogram
MBF3004-6-850
Monogram Composi-Lok II: "high strength blind bolt for composite and metallic materials" (catalog).

- Head Reduced protruding hex head
- Diameter 3/16" (-6)
- Grip .800-.850"
- Material Titanium
- Lead-time risk High
Install tool MP550BFDN-6AA, proprietary · Variable stack? Plan grips
CAD for MBF3004-6-850
| Family | Composi-Lok II (Monogram) |
|---|---|
| Head style | Reduced protruding hex head (source: Monogram drawing MBF3004 Rev U, title block, Tables I, III, note 4, material notes) |
| Nominal diameter | 3/16" (-6) |
| Grip | max grip .850" (grip range .800-.850", MBF3004 Rev U grip table) |
| Material | Titanium. Nut: 6Al-4V titanium alloy; screw: A286 CRES; sleeve: 304 stainless steel |
Decoded from the published numbering scheme; not a claim that this exact dash number is a stocked SKU, and not a certified design authority. Always verify against the controlling drawing, spec, and your stress group.
Dimensions
| A | Head hex across flats | .312/.305 |
| D | Nut shank diameter | .1985/.1965 |
| G | Max grip + G: datum to the end of the nut shank | .058(ref) |
| H | Head height | .080/.073 |
| L | Max grip + L: datum to the end of the screw | .675(ref) |
| Recom. Hole | Drilled hole | .202/.199 |
All dimensions (19)Fewer dimensions
| B | Head diameter over the hex corners | .340min |
| E | SLEEVE and SCREW head diameter (2X) | .1985max |
| F | SCREW wrench flats, on the tail | .113/.108 |
| R | NUT head-to-shank radius | .030max |
| T | DRIVE NUT hex across flats | .375(ref) |
| Min Avail. Grip | Min available grip dash | -100 |
| J | Installed blind head diameter | .300min |
| K | Installed: blind side protrusion | .420max |
| Break-Off | Screw break-off, measured from the skin surface | +.103/-.000 |
| Tensile | Tensile structural failure, min (lbs) | 1400min, lbs |
| Double Shear | Double shear, min (lbs) | 4600min, lbs |
| Locking Torque | Locking torque, min (in-lbs) | 1.5min, in-lbs |
| Grip limits | Dash 6-850 | .800-.850 |
As printed on MBF3004 Rev U sheet 1 ↗. Letters match the drawing.
Some features are scaled from the figure, not dimensioned.Scaled features
Scaled from the drawing's figure (not drawing dimensions)
| Component / feature | Scaled as | Model (in) |
|---|---|---|
| NUTnut nose diameter at its end (diameter) | 0.768 x D | .1516 |
| NUTnut nose end, from the datum | 0.162 x L - G | -1.0079 |
| NUTnut bore = screw thread crest diameter (diameter) | 0.713 x D | .1408 |
| SCREWscrew thread crest diameter (threads not modelled) | 0.713 x D | .1408 |
| SLEEVEsleeve bore over the nut nose and the insert (diameter) | 0.839 x D | .1656 |
| SLEEVEsleeve bore beyond the insert (diameter) | 0.729 x D | .1440 |
| INSERTinsert outside diameter (= sleeve bore) | 0.839 x D | .1656 |
| INSERTinsert inside diameter (= sleeve bore beyond the insert) | 0.729 x D | .1440 |
| INSERTinsert end, from the datum | 0.368 x L - G | -1.1348 |
| SLEEVEcrimp line (start of the crimped band), from the datum | 0.724 x L - G | -1.3545 |
| SCREWscrew head top (sleeve end), from the datum | 0.826 x L - G | -1.4179 |
| SCREWscrew head corner radius | 0.062 x E | .0122 |
| SLEEVEsleeve top, from the datum (where the scaled nose meets the scaled sleeve bore) | 0.112 x L - G | -.9774 |
| NUTnut nose taper (included angle) | angle, as drawn | 25.9° |
| DRIVE NUTdrive nut length | 1.064 x T | .3992 |
| DRIVE NUTdrive nut bearing diameter (cone end on the head) | 0.684 x T | .2567 |
| DRIVE NUTdrive nut bearing cone (half angle from the axis) | angle, as drawn | 30.9° |
| SCREWscrew tail beyond the drive nut | 1.056 x T | .3958 |
| SCREWwrench flats run: tail end to the drive nut (as drawn) | as drawn | .3958 |
Measured on MBF3004 Rev U sheet 1 figure at 300 dpi and kept as a ratio to a dimension this part number prints. Figure scale 450.6 px/in, fitting row -11, taken from D and E; checked against T (-0.1%), F (-1.5%), L - G (-6.4%).
Also printed in MBF3004 Rev U for this part
| Recommended hole | .199-.202 in (MBF3004 Rev U sheet 1) |
|---|---|
| Installed blind head | J .300 in min diameter (MBF3004 Rev U sheet 1) |
| Installed protrusion | K .420 in max (TYPICAL INSTALLATION) (MBF3004 Rev U sheet 1) |
| Break-off limits | +.103 -.000 in, measured from the skin surface (MBF3004 Rev U sheet 1) |
| Tensile | 1400 lbs min (structural failure) (MBF3004 Rev U sheet 1) |
| Double shear | 4600 lbs min (MBF3004 Rev U sheet 1) |
| Locking torque | 1.5 in-lbs min (MBF3004 Rev U sheet 1) |
| Min available grip | dash -100 (MBF3004 Rev U sheet 1) |
| Material and heat treat | NUT: 6Al-4V TITANIUM ALLOY PER AMS-T-9047 STA OR AMS4928 OR AMS4967 HEAT TREATED PER AMS-H-81200 TO 95 KSI SHEAR STRENGTH MINIMUM. MAXIMUM HYDROGEN CONTENT 125 PPM. SCREW: A286 CRES PER AMS5731, AMS5732 OR AMS5737 HEAT TREATED TO 175 KSI TENSILE MINIMUM. SLEEVE: 304 STAINLESS STEEL PER AMS5639, FULLY ANNEALED. INSERT: ACETAL PER ASTM-D4181 DRIVE NUT: MILD STEEL (MBF3004 Rev U material and finish notes) |
| Finish | ( - ) NUT: KAL-GARD ANN-RO #1012 CONVERSION COATING OR PHOSPHATE FLOURIDE PER MONOGRAM SPECIFICATION PS741, MAY BE USED AT MANUFACTURER'S OPTION. SLEEVE AND SCREW: PASSIVATE PER AMS2700, KAL-GARD ANN-RO #1013 CONVERSION COATING OPTIONAL. INSERT: NONE DRIVE NUT: COLOR BROWN (MBF3004 Rev U material and finish notes) |
| Lubricant | GRAPHITE FREE SOLID FILM LUBRICANT PER AS5272 OR MIL-PRF-81329, PARAFFIN WAX, OR CETYL ALCOHOL PER AS87132 (AS REQUIRED FOR PERFORMANCE). (MBF3004 Rev U material and finish notes) |
Series and strength (datasheet)
MBF2110 · MBF2111 · MBF2112 · MBF2113 · MBF2120 · MBF2121 · e.g. MBF2112-6-500
Rated shear 75 KSI (catalog comparison chart, MBF2112-06-500); 3/16" (-6) double shear 4,600 lb min, tensile 1,400 lb min, all materials & head styles (MBF2003 Table 10A).
Datasheet (PDF) ↗Section from Monogram drawing MBF3004 Rev U ↗ sheet 1.Drawing notes
Model: Monogram drawing MBF3004 Rev U
Envelope model, not manufacturer CAD.Model details
MBF3004-6-850, manufacturer nominal. Simplified component model from Monogram drawing MBF3004 Rev U sheet 1. Manufacturer nominal: printed values, the mean where only two limits are printed. Flush heads hold the printed head angle; the head depth is derived. Not manufacturer CAD. Verify against the current drawing before use. One named solid per component as the drawing calls them out (NUT, SCREW, SLEEVE, INSERT and, where the drawing has one, DRIVE NUT). Features the drawing shows without a dimension are scaled from its figure and listed as scaled in the STEP header; threads are not modelled. Axis +Z, head up, z = 0 at the face the head bears on. STEP (AP214) is in inches; STL has no units and is written in millimetres.
Other head styles, same diameter and grip
- MBF3003-6-850 low profile protruding head
- MBF3005-6-850 100° flush head
- MBF2013-6-850 130° flush head
MBF3004 grip chart: 3/16" (-6)
Every catalogued max-grip dash number at this diameter. Stack thickness must fall inside the fastener's grip range: see the design calculators.
Other diameters at this grip:
Threaded / torqued · 4 steps
1/4Inserted
“Insert the fastener in the hole. The Composi-Lok® II can be inserted in a properly prepared hole without interference.”
Monogram MBF2003 Rev AG (Composi-Lok II install spec), p.17, §7.2 ↗
Drawing traced from: Figure 15, left.
Source images (6): patent and government drawings
A patent drawing shows the patented design, which can differ in detail from today's catalog part. Each image says why it is tied to this family.






Install tooling
Install tooling: MP550BFDN-6AA (Monogram MBF2003 Rev AG (Composi-Lok II install spec), p.4, Table 1) · proprietary
- MGPCL Protruding head leaf gage (break-off check)
- RM3122-06 Removal nose piece module, protruding hex
Decode details
| Series | Composi-Lok IIa |
|---|---|
| Decode confidence | high |
| Numbering source | Monogram drawing MBF3004 Rev U, title block, Tables I, III, note 4, material notes |
- Grip dash = max grip in thousandths of an inch (MBF3004 Rev U grip table).
- Diameter dash per the drawing's basic-dimensions table (e.g. -6 = 3/16").
- Suffix "A" "designates dual drive nut system for robotic installation" (MBF2112 drawing note 1); MBF2003's installation tooling "not applicable to Composi-Lok II which have an 'A' suffix" (MBF2003 §1.1).
Government reference cross-reference (DLA FLIS)
MBF3004-6-850 is not listed in FLIS under this exact part number (FLIS data as of 2025-03-18, March 2025 snapshot). FLIS may record it with a material or finish code, or under the standard part number.
Source: DLA PUB LOG ↗. Search any part number in the decoder.
- Composi-Lok II by Monogram, blind bolt
- Datasheet (PDF) ↗
- Manufacturer page ↗
- Numbering: Monogram drawing MBF3004 Rev U, title block, Tables I, III, note 4, material notes ↗
- Geometry: MBF3004 Rev U ↗
Lead-time risk for this family (SpecLok sourcing assessment): High
Supply signal
Supply signalfor this part number
- Not listed in FLIS under this exact part number (March 2025 snapshot).
- No SpecLok quotes yet.
A signal from records SpecLok holds, not availability, stock or a lead-time promise. FLIS lists who has recorded a part number for the item, not who makes it today. DoD awards carry no NSN or part number, so award activity is for the item name's class.
Sources: DLA FLIS Data Electronic Reading Room (PUB LOG) ↗, DLA PUB LOG ↗, USAspending.gov award search API ↗; DoD award data 2025-10-01 to 2026-07-06; compiled 2026-09-28.
Image credits: Monogram Aerospace Fasteners, Monogram Aerospace Fasteners catalog, p.4 ↗. Product images belong to their manufacturers.
Sources
- Monogram drawing MBF3004 Rev U, title block, Tables I, III, note 4, material notes
- Monogram MBF2003 Rev AG (Composi-Lok II install spec)
- Composi-Lok II datasheet (PDF)
- Drawing MBF2112 material notes; catalog comparison chart rates MBF2112-06-500 at 75 KSI
- Drawing MBF2120 material notes; MBF2003 Table 10A strengths apply to "all materials & head styles"
- DLA PUB LOG
- DLA FLIS Data Electronic Reading Room (PUB LOG)
- USAspending.gov award search API
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