Crossbow Parts

[Dept of PMM Hall of Steel]

http://www.alcheminc.com/drawdata.HTMCrossbow Parts
Alchem serves as a reseller of finished prods and strings, and a machining service providing rough unfinished parts to crossbow manufacturers. We do not manufacture archery equipment, finished crossbows, or kits. Links to recommended manufacturers of these items may be found at the bottom of this page. The following is a list of materials and parts we currently supply. Many items are in stock and ready for immediate delivery. Others are produced in response to orders. Additionally we can supply some custom parts in large or small quantities. For a quote, submit a drawing and specifications. Please allow up to 6 weeks for delivery of custom orders.

Our crossbow prods now come with a six inch length of heat shrink tubing serving as a safety strap "sichern". These extend form the center of the prod outward, three inches on both sides. Safety straps are intended to reduce the chance of the shooter or a bystander being injured by a broken limb. Breakage, if it occurs, is nearly always confined to the area of maximum stress, from the center of the prod, to an inch or so beyond the point where the prod presses against the stock. This tubing should not be removed, since to do so creates a danger of injury to the user. If necessary, the safety strap may be covered with leather or some similar flexible material.

http://www.alcheminc.com/crossbow.html

Draw Weight

We currently manufacture a number of different crossbow prod models to provide our customers with a wide range of draw weights. We have determined that average draw weights will vary slightly from production batch to production batch due to differences in the thickness of the metal, the chemistry of the steel and its resulting hardness. Furthermore, draw weights will vary even within a given batch due to minor differences in the shape (tillering) of the parts. In the past these variations caused our customers a great deal of consternation. One of our customers, by the name of Gene Dwiggins of Rhode Island, built us a testing bench capable of rapidly and accurately determining the draw weight of a prod up to 300 pounds. Therefore we now test every prod we produce and record on its center belly the draw weight determined at 11.5 inches. This information makes it possible for a customer to order the exact draw weight desired. It also makes it possible to estimate the approximate draw weight and energy storage of a given prod when drawn to a distance shorter than the maximum recommended 11.5 inches. For this reason we have devised the following table. 

The following draw weight, draw length, and energy table has been compiled to include all of our prod models with a maximum recommended overall draw distance of 11.5 inches. In estimating draw weights and energies we assumed a brace height of 3.5 inches giving an actual maximum draw distance of 8 inches. Data was calculated down to 6 inches of actual draw since shorter draw lengths are not likely to be required by our customers. The following measurements are estimates. 

Distances are expressed in inches. Weights are in pounds. It should be noted that the "pound inch" figures following Weight x Draw are not equivalent to energy expressed in inch-pounds. 

The actual energy E required to draw a bow W a given distance D may be calculated as follows: 

E = .5 x W x D. 

W is the draw weight of the bow at distance D. 

	11.5" (8" draw)	11" (7.5" draw)	10.5" (7" draw)	10" (6.5" draw)	9.5" (6" draw)
Draw Weights	50	47	44	41	37
Weight x Draw	400	352	308	266	222
Inch Pounds	200	176	154	133	111
Draw Weights	55	52	48	45	41
Weight x Draw	440	390	336	292	246
Inch Pounds	220	195	168	146	123
Draw Weights	60	56	53	49	45
Weight x Draw	480	420	371	318	270
Inch Pounds	240	210	185	159	135
Draw Weights	65	61	57	53	49
Weight x Draw	520	457	399	344	294
Inch Pounds	260	228	199	172	147
Draw Weights	70	66	61	57	53
Weight x Draw	560	495	427	370	318
Inch Pounds	280	247	213	185	159
Draw Weights	75	70	66	61	56
Weight x Draw	600	525	462	396	336
Inch Pounds	300	262	231	198	168
Draw Weights	80	75	70	65	60
Weight x Draw	640	562	490	422	360
Inch Pounds	320	281	245	211	180
Draw Weights	85	80	74	69	64
Weight x Draw	680	600	518	448	384
Inch Pounds	340	300	259	224	192
Draw Weights	90	84	79	73	68
Weight x Draw	720	630	553	474	408
Inch Pounds	360	315	276	237	204
Draw Weights	95	89	83	77	71
Weight x Draw	760	667	581	500	426
Inch Pounds	380	333	290	250	213
Draw Weights	100	93	88	81	75
Weight x Draw	800	697	616	526	450
Inch Pounds	400	348	308	263	225
Draw Weights	105	98	92	85	79
Weight x Draw	840	735	644	552	474
Inch Pounds	420	367	322	276	237
Draw Weights	110	103	96	89	83
Weight x Draw	880	772	672	578	498
Inch Pounds	440	386	336	289	249
Draw Weights	115	108	101	93	86
Weight x Draw	920	810	707	604	516
Inch Pounds	460	405	353	302	258
Draw Weights	120	113	105	98	90
Weight x Draw	960	847	735	637	540
Inch Pounds	480	423	367	318	270
Draw Weights	125	117	109	102	94
Weight x Draw	1000	877	763	663	564
Inch Pounds	500	438	381	331	282
Draw Weights	130	122	114	106	98
Weight x Draw	1040	915	798	689	588
Inch Pounds	520	457	399	344	294
Draw Weights	135	127	118	110	101
Weight x Draw	1080	952	826	715	606
Inch Pounds	540	476	413	357	303
Draw Weights	140	131	123	114	105
Weight x Draw	1120	982	861	741	630
Inch Pounds	560	491	430	370	315
Draw Weights	145	136	127	118	109
Weight x Draw	1160	1020	889	767	654
Inch Pounds	580	510	444	383	327
Draw Weights	150	140	131	122	113
Weight x Draw	1200	1050	917	793	678
Inch Pounds	600	525	458	396	339
Draw Weights	155	145	136	126	116
Weight x Draw	1240	1087	952	819	696
Inch Pounds	620	543	476	409	348
Draw Weights	160	150	140	130	120
Weight x Draw	1289	1125	980	845	720
Inch Pounds	640	562	490	422	360
Draw Weights	165	155	144	134	124
Weight x Draw	1320	1162	1008	871	744
Inch Pounds	660	581	504	435	372
Draw Weights	170	159	149	138	128
Weight x Draw	1360	1192	1043	897	768
Inch Pounds	680	596	521	448	384
Draw Weights	175	164	153	142	131
Weight x Draw	1400	1230	1071	923	786
Inch Pounds	700	615	535	461	393
Draw Weights	180	169	158	146	135
Weight x Draw	1440	1230	1071	923	786
Inch Pounds	720	615	535	461	393
Draw Weights	185	173	162	150	139
Weight x Draw	1480	1297	1134	975	834
Inch Pounds	740	648	567	487	417
Draw Weights	190	178	166	154	143
Weight x Draw	1520	1335	1162	1001	858
Inch Pounds	760	667	581	500	429
Draw Weights	195	183	171	158	146
Weight x Draw	1560	1372	1197	1027	876
Inch Pounds	780	686	598	513	438
Draw Weights	200	188	175	163	150
Weight x Draw	1600	1410	1225	1059	900
Inch Pounds	800	705	612	529	450
Draw Weights	205	192	179	167	154
Weight x Draw	1640	1440	1253	1085	924
Inch Pounds	820	720	626	542	462
Draw Weights	210	197	184	170	158
Weight x Draw	1680	1477	1288	1105	948
Inch Pounds	840	738	644	552	474
Draw Weights	215	202	188	175	161
Weight x Draw	1720	1515	1316	1137	966
Inch Pounds	860	757	658	568	483
Draw Weights	220	206	193	179	165
Weight x Draw	1760	1545	1351	1163	990
Inch Pounds	880	772	675	581	495
Draw Weights	225	211	197	183	169
Weight x Draw	1800	1582	1379	1189	1014
Inch Pounds	900	791	689	594	507
Draw Weights	230	216	201	187	173
Weight x Draw	1840	1620	1407	1215	1038
Inch Pounds	920	810	703	607	519
Draw Weights	235	220	206	191	176
Weight x Draw	1880	1650	1442	1241	1056
Inch Pounds	940	825	721	620	528
Draw Weights	240	225	210	195	180
Weight x Draw	1920	1687	1470	1267	1080
Inch Pounds	960	843	735	633	540
Draw Weights	245	230	214	199	184
Weight x Draw	1960	1725	1498	1293	1104
Inch Pounds	980	862	749	646	552
Draw Weights	250	234	219	203	188
Weight x Draw	2000	1755	1533	1319	1128
Inch Pounds	1000	877	766	659	564

 

http://www.alcheminc.com/drawdata.HTM

 

[Dept of PMM Hall of Steel]

Prods 
The below listed items are made of high carbon spring steel which has been precisely hardened and tempered for optimal strength and durability. These are available in mill black or plain steel finish. Prods are shipped black and treated to resist rust unless otherwise requested. All models are available in a range of draw weights. When ordering, please specify the approximate weight desired and we shall match your request as closely as possible. Most of our models are designed for a recommended draw of 8 inches from a 3 1/2 inch brace. In other words, allow 11 1/2 inches from the mounted prod to the fingers of the release. The exception is model 6 which is designed for a recommended draw of 10 1/4 inches from a 4 1/2 inch brace. This equals a total distance of 14 3/4 inches from the center of the belly of the prod to the fingers of the release. A greater draw length should be avoided since this may lead to premature breakage of the part. For more detailed draw weight calculations and charts, go to our draw weight data page. 

 

MODEL	THICKNESS	LENGTH*	WIDTH C	WIDTH T	TIP RISE	APPROXIMATE DRAW WEIGHT IN POUNDS	PRICE EACH**	SHIPPING WEIGHT
1316	3/16"	28 1/2"	1 11/16"	11/16"	1/2"	120 to 140	$65 ($60 foreign)	1.68 lbs (.76 kg)
1732	7/32"	"	"	"	"	190 to 250	$65 ($60 foreign)	1.96 lbs (.89 kg)
2316	3/16"	"	1 3/16"	1/2"	"	90 to 110	$65 ($60 foreign)	1.25 lbs (.57 kg)
2732	7/32""	"	"	"	1/2"	150 to 190	$65 ($60 foreign)	1.25 lbs (.57 kg)
3316	3/16"	28 1/2"	1"	3/8"	1/2"	60 to 90	$65 ($60 foreign)	1.25 lbs (.57 kg)
3732	7/32"	28 1/2"	1"	3/8"	1/2"	125 to 150	$65 ($60 foreign)	1.25 lbs (.57 kg)
6316	3/16"	34"	1"	3/8"	0	50 to 75	$65 ($60 foreign)	1.25 lbs (.57 kg)
6732	7/32"	34"	1"	3/8"	0	80 to 110	$65 ($60 foreign)	1.25 lbs (.57 kg)

**(These prices include shipping to US addresses. Orders to be shipped to addresses outside the United States must have international shipping added. Our prods are all longer than 24 inches and must be shipped priority air. Follow this link for Global Parcel Post charges.) 

The following PayPal shopping cart buttons include estimated shipping charges. If you order several crossbow prods and overpay, the excess shipping charges will be refunded.

http://www.alcheminc.com/crossbow.html

[Dept of PMM Hall of Steel]

Strings 
Dacron B50 strings are now available to fit all of our prods. Remember to specify the model of prod when ordering. Strings sell for $14.00 if ordered and shipped with a prod or $15.00 if ordered alone. This price includes postage to customers in the US. Strings are available to foreign customers at a price of $14.00, but only when shipped along with another item.

http://www.alcheminc.com/crossbow.html

[Dept of PMM Hall of Steel]

Release Levers & Roller Nuts 
Rough cut steel release lever blanks identical to the one depicted on our plan below are available for $16.00 if ordered with a prod, or $18.00 if ordered alone. This price includes postage to customers in the US (Foreign customers pay $15.00 and add Global Parcel Post charges. Shipping weight 0.25 lbs (.11 kg).

http://www.alcheminc.com/crossbow.html

[Dept of PMM Hall of Steel]

Claplock Release Mechanisms & Levers 
Unfinished steel claplock release mechanisms, similar to the one depicted on our plan below, are available for $16.00 if ordered with a prod, or $18.00 if ordered alone. These consist of a clapper, hinge plate, and hinge pin. The purchaser must cut the sear to the required length and fabricate any necessary springs. This price includes postage to customers in the US (Foreign customers pay $15.00 and add Global Parcel Post charges. Shipping weight 0.25 lbs (.11 kg).

http://www.alcheminc.com/crossbow.html

[Dept of PMM Hall of Steel]

Bow Irons 
A photo of our bow irons in use may be seen by clicking here. These are shipped as sets consisting of 2 side plates, 2 blocks, 2 wedges and a stirrup. Sets are rough cut and require customization and finishing. These are designed to fit tillers from 1 1/2 inches to 2 1/4 inches thick. Sets sell for $32 with stirrup or $27 without. Stirrups alone sell for $5. This price includes postage to customers in the US (Foreign customers deduct $1 from the previous prices and add Global Parcel Post charges. Bow irons are available to fit either model 1 or model 2 prods. The wider model 1 irons will accommodate prod models 1, 2, 3, and 6. The narrower model 2 irons will accomodate prod models 2, 3, and 6. Bow irons should not be used with Fast Flite string. Shipping weight 1.20 lbs (.54 kg).

http://www.alcheminc.com/crossbow.html