AG | 5oz

This page contains our current information on 5oz class Engelhard Legacy Ingots and standard production bars. Some of Engelhard’s most notable Legacy Ingots were early production 5oz bars.  You will see below how rudimentary and varied the stamping methods were on these early examples, and it is this raw and classic appeal that many collectors find so alluring. With exception of these very limited Legacy Ingots illustrated below, Engelhard 5oz examples were considered standard production bars, yet only about 90,000  5oz bars were produced in total.  Nearly one-third of these bars were of the common extruded 9th series ‘C’ variety, with the balance divided between 30+ varieties over a span of 20+ years in the United States and Canada, rendering these bars highly collectible.  Also, important to note, is that a good percentage of these bars were melted over the years.

Presented below, we define all currently known varieties with pictures, serial numbers and mintage estimates.  There are surely a few more we haven’t encountered yet, and we welcome collectors to share any new discoveries.  We hope you enjoy your visit!

EXAMPLE	HALLMARK	OBVERSE	REVERSE	COMMENTARY	SAMPLE SERIAL NUMBERS	ICR | ESTIMATED MINTAGE
	‘E’ in Elongated Octagon	[Statue of Liberty]  [LIBERTY]	[Statue of Liberty Torch Logo]  [LIBERTY TRADE SILVER]  [.999+ FINE SILVER]  [FIVE TROY OUNCES]  [SERIAL NUMBER]  [© 1986 MTB]  [UNITED STATES OF AMERICA]	Specialty collector bar produced by Manfra, Tordella & Brookes, 1986 mintage.  Occasionally found with original assay certificate, which typically demands a higher valuation when present.  Some bars were included in a 1oz, 5oz & 10oz boxed commemorative set with estimated mintage of 1,000 total sets, pictured below.	A 0248 A 0423 A 1187 A 2755 A 2965 A 4880 A 5485	7,500 MINTAGE
	Maple Leaf Hallmark	[Engelhard ‘Maple Leaf’ Hallmark]  [ASSAYERS & REFINERS]  [5 TROY OUNCES]  [FINE SILVER 999 in Rectangle]  [Serial # in Rectangle with ‘Bull’ Logo]	Smooth Machined Finish with Border	5oz pressed commercial bar in Canadian variation, originally issued in sealed plastic.  This variety matches the 10oz Maple Leaf counterpart.  Bar 410107 sold privately on April 15, 2018 for $725.00.  Please note ingot 248785 [pictured below] is one of two known examples outside of 410xxx serial assignment range, which immediately follows the last poured 5oz Canadian ingot.	248776 248785 410107 410112 410114 410143 410149	<100 MINTAGE

EXAMPLE	HALLMARK	OBVERSE	REVERSE	COMMENTARY	SAMPLE SERIAL NUMBERS	ICR | ESTIMATED MINTAGE
	Top Hallmark	[Hallmark in Elongated Octagon]  [5.000]  [999]  [Serial Number]	Cast Finish	1st series ingot.  Crude casting finish, non ‘+’ variety.  Ingot 00384 sold privately on March 3, 2017 for $3,500.00.  Ingot 00359 sold via eBay auction on May 20, 2023 for $3,755.00.	00312 00326 00359 00364 00369 00370 00384 00394	<50 MINTAGE
	Top Hallmark	[Hallmark in Elongated Octagon]  [5.000]  [999]  [Serial Number]	Cast Finish	2nd series ingot.  Smoother casting finish, serial number range begins at 1,000.	01633 01651 02244 02733 03705	<200 MINTAGE
	Mid Hallmark	[5.000]  [999+]  [Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	3rd series ingot.  Casting dimension and distance between weight/purity stamps match those of 1st and 2nd series. Ingot 01253 sold privately on March 10, 2017 for $1,000.00.	01212 01220 01253 01306	<100 MINTAGE
	Mid Hallmark	[5.000]  [999+]  [Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	4th series ingot in 4-digit serial number variation.  Weight class and purity stampings are drawn closer together than previous variety, also common to all subsequent variety.  This obverse stamp set layout is familiar amongst later production 4th series variety.  Ingot 3805 sold privately on March 10, 2017 for $3,000.00.	3711 3760 3780 3805	<50 MINTAGE
	Mid Hallmark	[5.000]  [999+]  [Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	4th series ingot in large 4-digit serial number variation.  Ingot 3714 sold for $1,380.00 on April 3, 2016 via eBay auction.	3551 3555 3714	<50 MINTAGE
	Mid Hallmark	[5.000]  [999+]  [Hallmark in Elongated Octagon]	Cast Finish	4th series ingot in unique serial absent variation.  An example sold privately on March 3, 2017 for $2,500.00.  Another example sold via eBay auction for $2,373.00 on October 23, 2017.	N/A	<100 MINTAGE
	Mid Hallmark	[5.000]  [999+]  [Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	4th series in 5-digit serial variation with leading zero format.  Although this serial range spans approximately 6,000 numbers, production of this 5oz variety was very sparse within this run.	03955 04796 05056 05081 05329 05426 07259 09949	<250 MINTAGE
	Mid Hallmark	[5.000]  [999+]  [Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	4th series ingot in standard production variety.  Interesting 52335 example, also pictured, demonstrates a double-die hallmark. Basic casting shape and finish, as well as stamp set placement will vary slightly over entire serial number range.   Despite the seemingly wide serial number range, we believe these 5-digit ingots were only produced randomly in small runs and are, in fact, quite rare.	15648 18938 19038 19151 15034 25033 25034 35871 40014 48856 52335 61925 65871 78950 85539 85612	<2,500 MINTAGE
	Mid Hallmark	[5.000]  [999+]  [Hallmark in Elongated Octagon]  [Serial Number]  [MFR Designation]	Cast Finish	4th series in ‘MFR’ [Metals Fabrication & Refining] designation.  It is important to note that ‘MFR’ is not a serial number suffix as some collectors may claim.  The 100oz class examples confirm this as their serial number and ‘MFR’ designation are stamped on opposed corners of the ingot.  We believe there were intermittent overflow serial assignments with non ‘MFR’ designated ingots and that serial range is not indicative of mintage.  Ingot 54167 MFR sold via eBay auction on 7/30/23 for $810.11, and it was a marginal example with some surface scratches.	35704 ‘MFR’ 35794 ‘MFR’ 36517 ‘MFR’ 47242 ‘MFR’ 54102 ‘MFR’ 54175 ‘MFR’ 54187 ‘MFR’ 60175 ‘MFR’ 62311 ‘MFR’ 62359 ‘MFR’ 68754 ‘MFR’ 74175 ‘MFR’	<700 MINTAGE [Included in 2,500 4th series estimate, above]
	Left Hallmark	[Custom ‘UNITED’ Hallmark]  [5.000]  [999+]  [Serial Number]	Cast Finish	4th series in United Refining counterstamp variation.  Ingot 07913 sold via eBay auction for $1,027.55 on March 22, 2015.  Ingot 08239 sold privately for $2,500.00 on February 18, 2017.  Ingot 07867 sold on eBay auction for $3,722.99 on 6/10/23.  Additional information regarding the United Refining & Smelting counterstamp may be found at this LINK.	07857 07901 07913 07930 07964 08002 08003 08239	<100 MINTAGE
	Hallmark Absent	[5.000]  [999+]  [Serial Number]	Cast Finish	4th series in hallmark absent variation.  Believed to be an ingot produced for United Refining that was never hallmarked.  Ingot 07993 has an interesting Freemason stamp on the reverse.	07305 07993	<50 MINTAGE
	Mid Hallmark	[5.000]  [999+]  [Custom ‘SILVER DIAMOND CORPORATION’ Hallmark]  [Serial Number]	Cast Finish	4th series in Silver Diamond Corporation counterstamp variation.  These ingots were produced in a very tight serial  run that was shared with other variety, including the 3oz Ingot Mines. Ingot 329 sold privately on February 18, 2017 for $2,000.00.  Silver Diamond Corporation ingot 120 has been assay drilled through the center.   Additional information regarding the Silver Diamond Corporation counterstamp my be found at this LINK.	12 100 120 158 159 179 185 237 278 301 329 346 371 402 494	<500 MINTAGE
	Mid Hallmark	[5.000]  [999+]  [Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	5th series standard production ingot.  Large Mid Hallmark similar to 8th series design, often observed with a weak center stamp.  Despite this ingot’s larger center hallmark, we believe this is the next series in progression based on weight class stamp and serial number run.  Some serial numbers for this variety overlap those of 6th series variety.  We believe the serial number range is 50000 to 53999 with many 52xxx range assigned to 4th series pieces.	50077 50080 50090 51285 51840 52081 52081 52144 53544 53579	<1,300 MINTAGE
	Mid Hallmark	[5.000]  [999+]  [Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	5th series standard production ingot.  Similar to our above example, but includes the ‘X8′ serial prefix. Several examples have been logged lately with varying degrees of partial X8 / Y9 rotary stamp prefix impressions. Our appreciation to Christian and Tulasi for this discovery!	‘X8′ 50036 ‘X8′ 50809 ‘X8′ 52144 ‘X8′ 52452	<100 MINTAGE
	Mid Hallmark	[5.000]  [999+]  [Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish [FPM] Counterstamp	5th series standard production ingot.  Large Mid Hallmark design in [FPM] Fleet Precious Metals counterstamp.  Ingot 52400 sold privately on January 27, 2018 for $3,000.00.  Note the  different mould sizes of ingots 52285 and 52325.  Thanks to Todd W. for this discovery!  Additional information may be found at this LINK.	52288 52322 52326 52380 52400	<100 MINTAGE [Included in 1,300 5th series estimate, above]
	Mid Hallmark	[5.ooo]  [999+]  [Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	6th series standard production ingot. Note that the ‘5’ is larger than the zeroes.  Some serial numbers for this series include a zero prefix which appears to fall within the 054200 – 054999 range.  Total run of this series spans from 52750 to 55499, although this run was also shared with the 4th and 5th series above.	52750 53047 054246 054290 54024 54484 54744 55023 55282	<2,000 MINTAGE
	Mid Hallmark	[5.ooo]  [999+]  [Hallmark in Elongated Octagon]  [Serial Number]	N/A	Unique 5oz class ingot, additional information regarding this unique example, including his Australian relative, Ted, may be found at this LINK.	54307	1 MINTAGE
	Mid Hallmark	[5 T.OZ]  [Hallmark in Elongated Octagon]  [999+ FINE SILVER]  [Serial Number]	Cast Finish	7th series standard ‘T.OZ’ production ingot.  A leading ‘zero’ was added in the 059300 range that continued through end of production and the design was changed shortly thereafter.  All varieties are pictured for reference and, based on known serial numbers, we believe serial numbers span from 55500 to 061599.  Please note that at least two examples, 56855 and 56856 demonstrate the bottom foot of the number ‘2’ and the very top of number ‘3’ at the serial prefix position, as shown in the below photograph. There were at least two known pairs of identical serial number assignments in the 7th series standard ‘T.OZ’ production run.  One pair is owned by the founder of AE, serial number confirmation and photos are forthcoming.  The second pair of 56641 ingots is pictured below. Ingot 56672 demonstrates a serial number stamping error, pictured below.  This example was initially assigned serial number 56671 then subsequently overstamped and corrected to 56672.	55547 056011 056036 056050 56641 56672 56801 57018 58068 58755 59231 059322 059992 060268 061554	<4,000 MINTAGE
	Mid Hallmark	[5 T.OZ] [Hallmark in Elongated Octagon] [999+ FINE SILVER] [Serial Number]	[Serial Number]	7th series in standard production 5-digit serial variation. Similar to our example above, though includes reverse 57870 serial number stamping on back.  To date we have now verified over 25 examples showing this reverse stamp error, between the serial range of 57557 and 59004.  Interestingly, the 10 T.oz 5th Series ingot also shared a 57870 reverse stamp over a similar 1400 serial range.	57557 58019 58021 58423 58465 58654 58913 59004	<250 MINTAGE
	Mid Hallmark	[5 T.OZ]  [Hallmark in Elongated Octagon]  [999+ FINE SILVER]  [Serial Number]	Cast Finish	7th series ‘T.OZ’  ingot.  Several ingots were assigned a ‘-‘ minus prefix in the 57165 to 57390 range. This serial range was predominantly occupied by 10oz ingots so likelihood of material discovery is slim.  Earlier ingots 56873 and 56882 display a high minus suggesting it was likely a plate stamp indentation rather than a deliberate ‘-‘ prefix.	-57165 -57188 -57192 -57215 -57293 -57390	<100 MINTAGE
	Mid Hallmark	[5 T.OZ]  [Hallmark in Elongated Octagon]  [999+ FINE SILVER]  [Serial Number]	Cast Finish	7th series ‘T.OZ’ ingot.  This variation demonstrates an exceedingly rare ‘reversed’ convex stamping impression on the reverse, pictured, much like the reverse observed on 9th series ‘P’ prefix 10oz bars.  This stamping includes a double mirror-image of the 5 T.OZ detail as well as the larger hallmark found on 7th series 10oz  ingots.  Enlargement click of reverse enabled for better viewing of these details.  Ingot 061496 sold via eBay auction on September 18, 2017 for $860.00.  Ingot 061547 sold via eBay auction on November 5, 2017 for $982.50.	061496 061515 061517 061531 061547	<50 MINTAGE
	Mid Hallmark	[5 T.OZ]  [Hallmark in Elongated Octagon]  [999+ FINE SILVER]	Cast Finish	7th series ‘T.OZ’ ‘ ingot in rare serial absent variation.  One example sold via eBay auction on  October 12, 2016 for $853.00.	N/A	<100 MINTAGE
	Mid Hallmark	[999+]  [FINE SILVER]  [5 TR. OZ]  [Hallmark in Elongated Octagon]  [Serial Number]	Flat Machined Finish	8th series bar in ‘P’ serial prefix variation.  These bars are very similar in appearance to the common 10oz 10th series ‘P’ bars, yet this 8th series 5oz example had a surprisingly short production run for a later period Engelhard bar.  While the serial run of this series is projected from P00001 through P011800, we have noticed several sizeable gaps in serial ranges, and such gaps are utilized by other sizes and varieties of Engelhards, suggesting that the mintage of these may be far less than 10,000.  Early examples show a reverse “67” on the back of the bar.	P000039 P000135 P000671 P000841 P001431 P001949 P002553 P002558 P003538 P004632 P005249 P006380 P007763 P008169 P009476 P010353 P011770	<10,000 MINTAGE
	Top Hallmark	[Hallmark in Elongated Octagon]  [5 TROY OZ.]  [999+ FINE SILVER]  [Serial Number]	Hallmark in Elongated Octagon, repeated 3 full times, smooth pebbled finish	9th series bar in ‘C’ serial prefix variation. Like the 8th series ‘P’ 5oz bar, this series resembles its 10oz 12th series ‘P’ and ‘C’ counterparts.  This serial number run was shared with the 10oz 12th series ‘C’ prefix bars.	C200754 C200900 C206550 C214095 C216357 C218540 C223080 C244572 C244607	<25,000 MINTAGE
	Octagonal E-Insert	[5 OZ]  [Hallmark in Octagon]  [999. FINE]	[Serial Number]	Extruded 5oz bar.  Additional information may be found at this LINK.	-000322 -000324 -000331	<200 MINTAGE
	Top Hallmark	[Serial Number]	[Hallmark in Elongated Octagon]  [999 FINE]  [5 OZ]	Extruded 5oz bar in less frequently seen full-hallmark variation.  Interesting to note the reversal of obverse and reverse on this variety.  Additional information may be found at this LINK.	-000731 -000937 -000941 -000949	<100 MINTAGE

EXAMPLE	HALLMARK	OBVERSE	REVERSE	COMMENTARY	SAMPLE SERIAL NUMBERS	ICR | ESTIMATED MINTAGE
	Top Hallmark	[Australian Engelhard Hallmark]  [5 OZ]  [999+SILVER]	Cast Finish	5oz ingot in Australian variation, produced at the Engelhard refinery in Thomastown, Australia.  This variety lacks a decimal or dot between the ‘5’ and ‘OZ’, and the top of the ‘5 OZ’ faces the edge of the bar.	N/A	<250 MINTAGE
	Top Hallmark	[Australian Engelhard Hallmark]  [5•OZ]  [999+SILVER]	Cast Finish	5oz ingot in Australian variation, produced at the Engelhard refinery in Thomastown, Australia.  With this more rare example, there is a dot between the ‘5’ and ‘OZ’, and the top of ‘5 OZ’ faces the inside of the bar.  One example reportedly purchased new from Australian Bullion Company in 1984.  An example sold on 2/19/23 on Mineral Exchange auction for $1720 final sale price.	N/A	<100 MINTAGE

Our study of Canadian 5oz weight class pieces included several hundred examples and was conclusive enough to justify the presentation of six [6] series of ingot and only one [1] commercial bar series.  Our commentary column includes general information observed on the majority of pieces studied.  However, it is important to note that there were exceptions found during our studies.  For example, an ingot may occasionally  include a serial font specific to the United States whereas the majority of other pieces within the same series demonstrate a Canadian serial font.  We do not believe that serial number assignment is necessarily indicative of production order and that there were some variations in prefix assignment across all series.

EXAMPLE	HALLMARK	OBVERSE	REVERSE	COMMENTARY	SAMPLE SERIAL NUMBERS	ICR | ESTIMATED MINTAGE
	Mid Hallmark	[999+]  [5.000]  [Bull Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	1st series Canadian ingot in 5-digit serial variation.  This ingot’s 5-digit serial format, placement of weight/purity stampings and casting dimension are familiar to its 3rd series United States counterpart.  Canadian ingots across all weight class are typically observed in 6-digit serial format with purity stamping on left and weight class on right.  Based on this ingot’s dimension, we speculate Canada was initially provided with casting moulds used by the United States at that time for the first three series of Canadian ingots.  Ingot 89344 sold via eBay on March 11, 2016 for $809.00.	89229 89316 89326 89327 89344 89367	<150 MINTAGE
	Mid Hallmark	[999+]  [5.000]  [Bull Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	2nd series Canadian ingot in 5-digit serial variation.  This ingot shares 1st series hallmark and 5-digit serial format but the weight and purity stampings are reversed.  Based on this ingot’s dimension, we speculate Canada was initially provided with casting moulds used by the United States at that time for the first three series of Canadian ingots.	89309 89347 93195 96673 96846 97711	<500 MINTAGE
	Mid Hallmark	[999+]  [5.000]  [Bull Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	3rd series Canadian ingot in 6-digit serial variation. This ingot includes a hallmark stamp unique to 1st and 2nd series ingots.  Based on this ingot’s dimension, we speculate Canada was initially provided with casting moulds used by the United States at that time for the first three series of Canadian ingots.  We have observed examples with both United States and Canadian serial number fonts in this series and believe the serial numbers were assigned with specific prefix for each run.  We also believe there was not a continuous production run for the entire range of serial numbers. Note the variations in spacing between purity and weight stamps.  The variety with wider spacing is more commonly observed than the variety with narrow spacing. Photos of both are provided.	109592 110052 110103 110128 110141 114998 115931 116455 116994 122174 126259 146352 146558 167590 171396 171538 171578 171607	<5,000 MINTAGE
	Mid Hallmark	[999+]  [5.000]  [Bull Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	3rd series Canadian ingot in large 6-digit serial variation.  We believe this was a relatively intermittent serial run from 152200 to 152820 and a narrow range at around 168668.	152217 152300 152366 152385 152514 152714 152767 152817 168668	<500 MINTAGE
	Mid Hallmark	[999+]  [5•000]  [Bull Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	4th series ingot in Canadian variation.  First Canadian variety to include the ‘floating decimal’ on weight class and oddly demonstrates the purity font of 5th series United States ingot.  Serial number font common to 1st series Canadian examples, very unique and rare ingot. Our thanks to Damien M. for this find!	97952 98010 98012	<25 MINTAGE
	Mid Hallmark	[999+]  [5•000]  [Bull Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	5th series ingot in Canadian variation.  First Canadian variety to include the new font for purity 9’s common to subsequent Canadian production.  United States serial number font was still being applied on most examples studied.  Based on this ingot’s dimension, we speculate Canada was initially provided with casting moulds used by the United States at that time for the first three series of Canadian ingots.  Ingot 193191 sold privately on April 1, 2017 for $1,000.00. The photo below demonstrates the difference between this 5th series and the 7th series, which has identical stamping but a larger mould size.	171668 171679 171860 171906 193191 215785 215797 215799 215846 215851	<250 MINTAGE
	Mid Hallmark	[999+]  [5•000]  [Bull Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	6th series ingot in Canadian variation.  We believe this series ingot to be the first truly ‘All Canadian’ 5oz variety.  Features a casting mould, font set, and stamp placement unique to only Canadian examples.  Serial font is larger and uniquely Canadian, specifically the number ‘1’ has a horizontal bar at the top and does not angle down as seen on US font set.  Also unique are the fully-curved ‘3’ numbers vs. the United States serial font.  We believe these pieces were produced in two runs, specifically prefix ‘135’ and ‘193’ both pictured.  Example 193097 demonstrates a weight class stamping error, pictured below.	133337 135690 135741 135748 193013 193044 193057 193059 193071 193097	<150 MINTAGE
	Mid Hallmark	[999+]  [5•000]  [Bull Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	6th series ingot in Canadian variation.  Similar to our example above, but demonstrates a unique ‘1’ prefix that we believe was applied to correct a serial stamping error, wherein the digit ‘1’ was not correctly applied.  Note the font of this  ‘1’ digit is different than demonstrated on our above entry, and it is  slightly misaligned due to being individually hand applied.  Our appreciation to Dan S. for this discovery!	193036	<5 MINTAGE
	Mid Hallmark	[999+]  [5•000]  [Bull Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	7th series ingot in Canadian variation.  Some examples observed with casting striations on the reverse familiar to other Canadian weight class, pictured.  Also pictured is an example with serial number and casting finish unique to this series.	195762 201139 203276 214351 215348 215581 215782 235560 235646 236377 236673 235949 239762 240068 242783 247990 248574 248763	<7,500 MINTAGE
	Mid Hallmark	[999+]  [5•000]  [Bull Hallmark in Elongated Octagon]  [Serial Number]	Cast Finish	7th series ingot in Canadian variation.  These examples demonstrate a ‘1•’ serial number prefix, such as the 1•212925 bar pictured, which was applied to eliminate inadvertent duplication of serial numbers. Note the unique reverse pattern on example 1•212895.  Ingot 1•213057 sold privately on October 2, 2017 for $1,000.00.	1•212895 1•212925 1•213029 1•213041 1•213052 1•213056 1•213057 1•213085 1•213177	<300 MINTAGE [Included in 7,500 estimate, above]
	Mid Hallmark	[999+]  [5•000]  [Bull Hallmark in Elongated Octagon]  [Serial Number]	Smooth Machined Finish	8th series machined bar in Canadian variation, last known variety produced.	219792 219795 219818 219836 219837 219977	<200 MINTAGE

• Most Engelhard 5oz class silver bars have serial numbers.  Exceptions include Australian examples and seldom seen serial absent variety, believe to be an error piece.
• We believe the crudely finished top hallmark examples in non ‘+’ format was the first 5oz ingot produced.
• Serial number range for United States pieces in 5-digit and 6-digit serial format appears to span from 00001 to 90000 with several design changes and of course overflow serial numbers on some examples.
• The 6-digit variety with ‘zero’ prefix were produced after the majority of 5-digit pieces and do include some overlap of some simultaneously produced 5-digit pieces.
• The letter prefix ‘P’ series and ‘C’ series were produced after the 6-digit non-letter prefix United States examples and in that order.
• There are unsubstantiated claims that ‘P’ represents ‘poured’ and ‘C’ represents ‘cast’ in serial prefix.  We challenge this theory as it was the casting method by which Engelhard produced their poured ingots.  Casting is quite similar to making ice cubes in a freezer, in that liquid [molten metal] is used to create a solid ingot by use of a mould.  As such, the terms ‘poured’ and ‘cast’ are synonymous.  Further, Engelhard would not have had the foresight to designate a ‘P’ prefix in anticipation of the ‘C’ prefix series as the advancement of production technology was not foreseeable when they designated the ‘P’ prefix.