Taken from ASR with permission from aznriptide859, all credit to him and those who contributed to this thread. "In my experience I noticed that a LOT of normal hardware parts (electrical, plumbing, etc) can all be used for airsoft applications ranging from compression fixes, mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock mock suppressors, and even spring spacers. It's disgusting how much airsoft retailers/manufacturers make off of simple parts you can replace with just stuff you can find at hardware stores. I think it'd be great to list a few parts that will help many airsofters on the forums. If you have something to add, please post . I have added personal notes to whether they have worked for me or not. Database for Hardware-Related Airsoft Parts by aznriptide859 From McMaster-Carr (mcmaster-carr.com) Piston X-rings (Non-Boreup) Part 6540K167 (Viton) - $9.06 for pack of 10 Part 90025K238 (Duro) - $12.72 for pack of 100 Note: Vitons CONFIRMED working. However, Duro results from one user has shown completely failure in compression for multiple guns. Until further notice/further testing from other members, please refrain from buying the Duro ones. Plus, the Viton ones are better Piston X-rings (Boreup) - courtesy of sdobbins Part 6540K141 (Viton) - $9.93 for pack of 10 Part 90025K244 (Buna) - $13.00 for pack of 100 Note: NOT CONFIRMED Cylinder X-rings (Non-Boreup) Part 6540K129 (Viton) - $12.67 for pack of 25 Part 90025K361 (Buna) - $12.06 for pack of 100 Note: Might not fit some, as the diameter needed is in metric (MMC doesn't provide metric for O-rings). Cylinder X-rings (Boreup) Part 6540K166 (Viton) - $12.67 for pack of 25 Part 90025K362 (Buna) - $12.10 for pack of 100 Note: Not confirmed AEG M4 Charging Handle Enhanced Return Springs Part 9654K416 (1-1/2" L, 7/32" OD, 0.023" Wire) - $7.53 for pack of 12 These are basically the return springs for AEG M4 charging handles - a LOT stronger than stock ones. Handles with these springs will now return faster and will not deform over time/heavy usage. CONFIRMED working. Small Size Metric Allen Wrenches Part 7289A31 (0.7mm Hex, 1-5/16") - $0.15 each Part 7289A32 (0.9mm Hex, 1-5/16") - $0.15 each Part 7289A33 (1.3mm Hex, 1-3/4") - $0.12 each Part 7289A11 (1.5mm Hex, 1-3/4") - $0.18 each 0.9mm is used most for GBB small grub screws (such as in the TM 5-7 and KWA MP7), while 1.5mm and 1.3mm is used mostly for flash hider grub screws and other miscellaneous items. 0.7m are for very smaller screws such as G18 AEP's and the like. All CONFIRMED working. GBB Fill Valve O-rings Part 9452K111 (AS568A-001) - $1.87 for pack of 100 Part 9452K311 (AS568A-001-1/2) - $2.82 for pack of 100 Part 9452K112 (AS568A-002) - $1.87 for pack of 100 Note: -001 is confirmed to fit TM fill valves, but unfortunately they caused filling issues so I took them off - use with caution. I haven't used -002 yet, but I suspect they can be used for larger valves (i.e. 40mm grenades). Also, the use of needlenose tweezers to stretch the O-ring is absolutely necessary - McMaster sells those as well if you don't have any already. On a sidenote, user Karab has informed me that he managed to use -002 O-rings for his KWA M9 PTP just fine - this technically should mean it will work with other KWA magazines, but do take that advice with a grain of salt. Flash Hider/Misc. 1.5mm Grub Hex Screws Part 91390A099 (M3, 1.5mm x 5mm) - $4.77 for pack of 100 These are general grub/hex screws you find for flash hiders and other small items that require locking with something. Note: CONFIRMED working. Spare Gearbox Screws (+ head) - Courtesy of ImmortalZod Part 92000A118 (M3, 8mm) - $4.35 for pack of 100 Part 92010A126 (M3, 16mm) - $7.03 for pack of 100 The 8mm screws will be for the top screws (those on top of the cylinder assembly), while the 16mm ones will be for the rest (they are conical so will fit flush with the gearbox's externals). Note: CONFIRMED working by ImmortalZod. BAR-10 Scope Rail Screws - Courtesy of ctres94 Part 92855A313 (M3, 12mm) - $3.83 for pack of 25 Quote from: ctres94 on August 16, 2011, 04:26:08 PM Part #92855A313 m3 screws in 12mm length for Bar 10 scope rail. You might want to note that any m3X12 screw with a .5mm pitch will work, the ones I got were simply the cheapest and are silver as opposed to black. These work perfectly and screw in really smoothly. I got these because my stock ones were only 8mm and were to short. Note: CONFIRMED working by ctres94. Angle of Engagement Piston Adjustment Nylon Spacers Part 95606A180 (0.028"-0.034" thick) - $7.52 for pack of 100 Part 95630A445 (0.027"-0.035" thick) - $4.39 for pack of 10 (thanks grmash) Note: CONFIRMED working. The 2nd listing is for a bushing that covers the entire area of the piston head. The 1st one is for a bushing that just goes around the outer diameter of the piston. The 1st one is cheaper, but it might allow for possible spacer movement - the 2nd one is preferred. Here is a picture showing what I mean - A180 on the left, A445 on the right. Polyurethane/Sorbothane Pads Part 8514K51 (1/8" thick, 40/50/70D) - $4.85 for 4" x 4" sheet Part 8514K52 (3/16" thick, 40/50/70D) - $5.37 for 4" x 4" sheet Part 8514K53 (1/4" thick, 40/50/70D) - $6.44 for 4" x 4" sheet D refers to durometer, or how hard the material is. Harder durometers are suggested for stronger springs (over 400fps) and softer ones are suggested for weaker springs. Do note with thicker pads, you may need to short stroke and do AoE adjustments for the piston. Note: CONFIRMED from other sources, however I will most likely do some tests of my own to make sure. Standby for further testing. TPE - Polyethylene - Courtesy of meancivicsi Part 8657K112 (1/8" thick, 42-66D) - $3.66 for 12" x 12" sheet Part 8657K113 (3/16" thick, 42-66D) - $5.31 for 12" x 12" sheet Part 8657K114 (1/4" thick, 42-66D) - $7.39 for 12" x 12" sheet Part 8619K441 (1/8" thick, 62-69D) - $4.03 for 12" x 12" sheet Part 8619K451 (3/16" thick, 62-69D) - $5.66 for 12" x 12" sheet Part 8619K461 (1/4" thick, 62-69D) - $7.36 for 12" x 12" sheet Read here for more info: http://www.airsoftretreat.com/forums/index.php?topic=72093.0 TPE = thermoplastic elastomer. The lowest durometers I found were under polyethylene, so hopefully these could work. Same mods are applied to TPE as with sorbothane/polyurethane. NOTE: Above TPE were tested by utc_pryo and are not soft enough to register as an effective damper product. I'll research around and find an alternative, but in the meantime, don't get it. Hopup Resistance O-Rings - Courtesy of TehFish Part 2418T117 (Duro, -11, Medium-Soft, Milspec) - $9.97 for pack of 115 Part 1879T17 (Duro, -11, Hard) - $2.96 for pack of 100 Read here for more info: http://www.airsoftretreat.com/forums/index.php?topic=40038.msg436432#msg436432 I have 2 options for the -11 O-ring since TF mentioned they should be soft, but the only ones that are med-soft are MilSpec ones - Std ones are hard/very hard. User Maydie has claimed to also use #6 O-rings from his local hardware store for the same mod. Note: CONFIRMED, at least the 1st part was. I use these on my Recce rifle, and the durometer is soft enough to where you can adjust it easily with a number of O-rings. I would suggest the 1st over the 2nd. 40mm Grenade Bearings Part 9528K12 (5/32", for Madbull or larger-bearing grenades) - $3.15 for pack of 100 Part 9292K33 (3mm, for KA/Moscart or smaller-bearing grenades) - $6.05 for pack of 100 Grenade reset valve bearings for any 40mm gas grenade. Note: Larger sizes CONFIRMED working. Smaller sizes were confirmed by Lon3Wo1f. Tappet Plate Bearings - Courtesy of sdobbins Part 9292K31 (Alloy Steel, 2mm) - $6.16 for pack of 100 Part 1598K18 (Stainless Steel, 2mm) - $10.60 for pack of 250 Part 9614K71 (Delrin, 2mm) - $1.68 for pack of 100 Read here for more info: http://www.airsoftretreat.com/forums/index.php?topic=77728.0 Motor Connectors, Double Crimp Part 69525K59 - $1.47 for pack of 10 (16-14AWG wiring), $5.71 for pack of 100 Note: All CONFIRMED working, basically exact same size as those found in AEG's, but a lot tougher than stock/ACM ones. Right-Angle Motor Connectors Part 7769K31 - $1.56 for a pack of 10 (18-22AWG wiring), $6.76 for a pack of 100 Part 7769K33 - $1.56 for a pack of 10 (14-16AWG wiring), $6.76 for a pack of 100 Similar to previously mentioned motor connectors, simply already bent for you. Note: CONFIRMED via other sources. M249 Feeding Springs/Tubes - Courtesy of killbucket Part 9664K49 - $3.36 for 3 feet Part 3038K192 - $11.60 for 10 feet Read here for more info: http://www.airsoftretreat.com/forums/index.php?topic=66101.0 Note: Do not have M249, but via killbucket's thread this will work. 1/16''-thick RDS/Scope Plexiglass Protectors Part 8574K24 - $4.07 for 12'' x 12'' Part 8574K38 - $6.94 for 12'' x 24'' Part 8574K51 - $12.42 for 24'' x 24'' Note: CONFIRMED working. Wire Mesh (Perforated Steel) - 41% Viewing Area Part 9255T251 - $39.73 for 36" x 40" Same mesh that Bitter End uses in their mesh goggles - perforated steel (VERY strong), and NOT woven mesh. However I cannot endorse that these provide better protection than ANSI-approved lenses for googles; use at your own risk. Note: Never attempted, though uscmCorps of Arnie's has used it on a "Heat" mask."