QuickLinks -- Click here to rapidly navigate through this document

Exhibit 12.1

METALDYNE CORPORATION
Computation Of Ratio Of Earnings To Combined Fixed Charges And
Preferred Stock Dividends
(Dollars in thousands)

	3 Months Ended April 3, 2005			3 Months Ended March 28, 2004			Year Ended January 2, 2005			Year Ended December 28, 2003			Year Ended December 29, 2002			Year Ended December 31, 2001			11/28–12/31 2000
													(Restated)			(Restated)			(Restated)
EARNINGS (LOSS) BEFORE INCOME TAXES AND FIXED CHARGES:
Income (loss) from continuing operations before income taxes and cumulative effect of accounting change, net	$	(5,390	)	$	(5,490	)	$	(64,860	)	$	(83,990	)	$	(69,090	)	$	(47,040	)	$	(42,820	)
(Deduct) add equity in undistributed earnings (loss) of less-than-fifty percent owned companies		(610	)		(1,460	)		(1,450	)		20,700			1,410			8,930			1,000
Add interest on indebtedness, net		22,600			20,100			82,140			75,510			91,000			148,160			14,440
Add amortization of debt expense		780			670			3,880			2,480			4,770			11,620			550
Add preferred stock dividends and accretion		5,440			4,260			19,900			—			—			—			—
Estimated interest factor for rentals (d)		4,650			4,170			16,480			12,930			12,460			9,730			310
Earnings before income taxes and fixed charges	$	27,470		$	22,250		$	56,090		$	27,630		$	40,550		$	131,400		$	(26,520	)
FIXED CHARGES:
Interest on indebtedness, net	$	22,600		$	20,100		$	82,140		$	75,510		$	91,000		$	148,160		$	14,440
Amortization of debt expense		780			670			3,880			2,480			4,770			11,620			550
Preferred stock dividends and accretion		5,440			4,260			19,900			—			—			—			—
Estimated interest factor for rentals (d)		4,650			4,170			16,480			12,930			12,460			9,730			310
Total fixed charges		33,470			29,200			122,400			90,920			108,230			169,510			15,300
Preferred stock dividends (a)		—			—			—			10,320			13,090			6,430			620
Combined fixed charges and preferred stock dividends	$	33,470		$	29,200		$	122,400		$	101,240		$	121,320		$	175,940		$	15,920
Ratio of earnings to fixed charges		—	(b)		—	(b)		—	(b)		—	(b)		—	(b)		—	(b)		—	(b)
Ratio of earnings to combined fixed charges and preferred stock dividends		—	(c)		—	(c)		—	(c)		—	(c)		—	(c)		—	(c)		—	(c)

(a)

Based on the Company's effective tax rate, represents the amount of income before provision for income taxes required to meet the preferred stock dividend requirements of the Company and its 50% owned companies.

(b)

Results of operations for the three months ended April 3, 2005 and March 28, 2004, years ended January 2, 2005, December 28, 2003, December 29, 2002 (as restated) and December 31, 2001 (as restated) and the 34 days ended December 31, 2000 (as restated) are inadequate to cover fixed charges by $6,000, $6,950, $66,310, $63,290, $67,680, $38,110 and $41,820, respectively

(c)

Results of operations for the three months ended April 3, 2005 and March 28, 2004, years ended January 2, 2005, December 28, 2003, December 29, 2002 and December 31, 2001 and the 34 days ended December 31, 2000 are inadequate to cover fixed charges and preferred stock dividends by $6,000, $6,950, $66,310, $73,610, $80,770, $44,540 and $42,440, respectively.

(d)

Deemed to represent one-third of rental expense on operating leases.

QuickLinks

METALDYNE CORPORATION Computation Of Ratio Of Earnings To Combined Fixed Charges And Preferred Stock Dividends (Dollars in thousands)